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Chapter 4

Fractions — Exercise 4(F)

Class - 6 RS Aggarwal Mathematics Solutions



Exercise 4(F)

Question 1

Find:

(i) 18\dfrac{1}{8} of 40

(ii) 411\dfrac{4}{11} of 4254\dfrac{2}{5}

(iii) 1351\dfrac{3}{5} of 6146\dfrac{1}{4}

(iv) 34\dfrac{3}{4} of ₹ 1

(v) 58\dfrac{5}{8} of 1 km

(vi) 512\dfrac{5}{12} of 1 hour

Answer

(i) 18\dfrac{1}{8} of 40

⇒18×40⇒1×408⇒408⇒5\Rightarrow \dfrac{1}{8} \times 40\\[1em] \Rightarrow \dfrac{1 \times 40}{8}\\[1em] \Rightarrow \dfrac{40}{8}\\[1em] \Rightarrow 5

Hence, 18\dfrac{1}{8} of 40 = 5.

(ii) 411\dfrac{4}{11} of 4254\dfrac{2}{5}

⇒411×425⇒411×225⇒45×2211⇒45×2⇒85⇒135.\Rightarrow \dfrac{4}{11} \times 4\dfrac{2}{5}\\[1em] \Rightarrow \dfrac{4}{11} \times \dfrac{22}{5}\\[1em] \Rightarrow \dfrac{4}{5} \times \dfrac{22}{11}\\[1em] \Rightarrow \dfrac{4}{5} \times 2 \\[1em] \Rightarrow \dfrac{8}{5}\\[1em] \Rightarrow 1\dfrac{3}{5}.

Hence, 411 of 425=135\dfrac{4}{11} \text{ of } 4\dfrac{2}{5} = 1\dfrac{3}{5}.

(iii) 1351\dfrac{3}{5} of 6146\dfrac{1}{4}

⇒135×614⇒85×254⇒8×255×4⇒20020⇒10.\Rightarrow 1\dfrac{3}{5} \times 6\dfrac{1}{4}\\[1em] \Rightarrow \dfrac{8}{5} \times \dfrac{25}{4}\\[1em] \Rightarrow \dfrac{8 \times 25}{5 \times 4}\\[1em] \Rightarrow \dfrac{200}{20}\\[1em] \Rightarrow 10.

Hence, 135 of 614=101\dfrac{3}{5} \text{ of } 6\dfrac{1}{4} = 10.

(iv) 34\dfrac{3}{4} of ₹ 1

⇒34×₹1⇒34×100 paise⇒3×1004 paise⇒3004 paise⇒75 paise\Rightarrow \dfrac{3}{4} \times ₹ 1\\[1em] \Rightarrow \dfrac{3}{4} \times 100 \text{ paise}\\[1em] \Rightarrow \dfrac{3 \times 100}{4}\text{ paise}\\[1em] \Rightarrow \dfrac{300}{4}\text{ paise}\\[1em] \Rightarrow 75\text{ paise}

Hence, 34\dfrac{3}{4} of ₹ 1 = 75 paise.

(v) 58\dfrac{5}{8} of 1 km

⇒58×1 km⇒58×1000 m⇒5×10008 m⇒50008 m⇒625 m\Rightarrow \dfrac{5}{8} \times 1\text{ km}\\[1em] \Rightarrow \dfrac{5}{8} \times 1000\text{ m}\\[1em] \Rightarrow \dfrac{5 \times 1000}{8}\text{ m}\\[1em] \Rightarrow \dfrac{5000}{8}\text{ m}\\[1em] \Rightarrow 625\text{ m}\\[1em]

Hence, 58\dfrac{5}{8} of 1 km = 625 m.

(vi) 512\dfrac{5}{12} of 1 hour

⇒512×1 hour⇒512×60 min⇒5×6012 min⇒30012 min⇒25 min\Rightarrow \dfrac{5}{12} \times 1 \text{ hour}\\[1em] \Rightarrow \dfrac{5}{12} \times 60 \text{ min}\\[1em] \Rightarrow \dfrac{5 \times 60}{12} \text{ min}\\[1em] \Rightarrow \dfrac{300}{12} \text{ min}\\[1em] \Rightarrow 25 \text{ min}\\[1em]

Hence, 512\dfrac{5}{12} of 1 hour = 25 min.

Question 2

Simplify :

116÷159×3131\dfrac{1}{6} ÷ 1\dfrac{5}{9} \times 3\dfrac{1}{3}

Answer

Solving,

⇒116÷159×313⇒76÷149×103⇒76×914×103⇒714×93×106⇒12×3×53⇒52⇒212.\Rightarrow 1\dfrac{1}{6} ÷ 1\dfrac{5}{9} \times 3\dfrac{1}{3}\\[1em] \Rightarrow \dfrac{7}{6} ÷ \dfrac{14}{9} \times \dfrac{10}{3}\\[1em] \Rightarrow \dfrac{7}{6} \times \dfrac{9}{14} \times \dfrac{10}{3}\\[1em] \Rightarrow \dfrac{7}{14} \times \dfrac{9}{3} \times \dfrac{10}{6}\\[1em] \Rightarrow \dfrac{1}{2} \times 3 \times \dfrac{5}{3}\\[1em] \Rightarrow \dfrac{5}{2}\\[1em] \Rightarrow 2\dfrac{1}{2}.

Hence, 116÷159×313=2121\dfrac{1}{6} ÷ 1\dfrac{5}{9} \times 3\dfrac{1}{3} = 2\dfrac{1}{2}.

Question 3

Simplify :

113÷371\dfrac{1}{3} ÷ \dfrac{3}{7} of 258+1192\dfrac{5}{8} + 1\dfrac{1}{9}

Answer

Solving,

⇒113÷37 of 258+119⇒43÷(37×218)+109⇒43÷3×217×8+109⇒43÷6356+109⇒43÷98+109⇒43×89+109⇒4×83×9+109⇒3227+109⇒3227+10×39×3⇒3227+3027⇒32+3027⇒6227⇒2827\Rightarrow 1\dfrac{1}{3} ÷ \dfrac{3}{7} \text{ of } 2\dfrac{5}{8} + 1\dfrac{1}{9}\\[1em] \Rightarrow \dfrac{4}{3} ÷ \Big(\dfrac{3}{7} \times \dfrac{21}{8}\Big) + \dfrac{10}{9}\\[1em] \Rightarrow \dfrac{4}{3} ÷ \dfrac{3 \times 21}{7 \times 8} + \dfrac{10}{9}\\[1em] \Rightarrow \dfrac{4}{3} ÷ \dfrac{63}{56} + \dfrac{10}{9}\\[1em] \Rightarrow \dfrac{4}{3} ÷ \dfrac{9}{8} + \dfrac{10}{9}\\[1em] \Rightarrow \dfrac{4}{3} \times \dfrac{8}{9} + \dfrac{10}{9}\\[1em] \Rightarrow \dfrac{4 \times 8}{3 \times 9} + \dfrac{10}{9}\\[1em] \Rightarrow \dfrac{32}{27} + \dfrac{10}{9}\\[1em] \Rightarrow \dfrac{32}{27} + \dfrac{10 \times 3}{9 \times 3}\\[1em] \Rightarrow \dfrac{32}{27} + \dfrac{30}{27}\\[1em] \Rightarrow \dfrac{32 + 30}{27}\\[1em] \Rightarrow \dfrac{62}{27}\\[1em] \Rightarrow 2\dfrac{8}{27}

Hence, 113÷371\dfrac{1}{3} ÷ \dfrac{3}{7} of 258+119=28272\dfrac{5}{8} + 1\dfrac{1}{9} = 2\dfrac{8}{27}.

Question 4

Simplify :

615÷31106\dfrac{1}{5} ÷ 3\dfrac{1}{10} of 212÷142\dfrac{1}{2} ÷ \dfrac{1}{4}

Answer

⇒615÷3110 of 212÷14⇒615÷(3110×52)÷14⇒615÷31×510×2÷14⇒615÷15520÷14⇒(615÷314)÷14⇒(315÷314)÷14⇒(315×431)÷14⇒45÷14⇒45×4⇒165⇒315.\Rightarrow 6\dfrac{1}{5} ÷ 3\dfrac{1}{10} \text{ of } 2\dfrac{1}{2} ÷ \dfrac{1}{4}\\[1em] \Rightarrow 6\dfrac{1}{5} ÷ \Big(\dfrac{31}{10} \times \dfrac{5}{2}\Big) ÷ \dfrac{1}{4}\\[1em] \Rightarrow 6\dfrac{1}{5} ÷ \dfrac{31 \times 5}{10 \times 2} ÷ \dfrac{1}{4}\\[1em] \Rightarrow 6\dfrac{1}{5} ÷ \dfrac{155}{20} ÷ \dfrac{1}{4}\\[1em] \Rightarrow \Big(6\dfrac{1}{5} ÷ \dfrac{31}{4}\Big) ÷ \dfrac{1}{4}\\[1em] \Rightarrow \Big(\dfrac{31}{5} ÷ \dfrac{31}{4}\Big) ÷ \dfrac{1}{4}\\[1em] \Rightarrow \Big(\dfrac{31}{5} \times \dfrac{4}{31}\Big) ÷ \dfrac{1}{4}\\[1em] \Rightarrow \dfrac{4}{5} ÷ \dfrac{1}{4} \\[1em] \Rightarrow \dfrac{4}{5} \times 4 \\[1em] \Rightarrow \dfrac{16}{5}\\[1em] \Rightarrow 3\dfrac{1}{5}.

Hence, 615÷31106\dfrac{1}{5} ÷ 3\dfrac{1}{10} of 212÷14=3152\dfrac{1}{2} ÷ \dfrac{1}{4} = 3\dfrac{1}{5}.

Question 5

Simplify :

323−3113\dfrac{2}{3} - \dfrac{3}{11} of 234÷114×123+132\dfrac{3}{4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}

Answer

⇒323−311 of 234÷114×123+13⇒323−311×234÷114×123+13⇒323−311×114÷114×123+13⇒323−3×1111×4÷114×123+13⇒323−3×1111×4÷114×123+13⇒323−34÷114×123+13⇒323−34÷54×123+13⇒323−34×45×53+13⇒323−3×4×54×5×3+13⇒323−1+13⇒113+13−1⇒11+13−1⇒123−1⇒4−1⇒3\Rightarrow 3\dfrac{2}{3} - \dfrac{3}{11} \text{ of } 2\dfrac{3}{4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3}{11} \times 2\dfrac{3}{4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3}{11} \times \dfrac{11}{4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3 \times 11}{11 \times 4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3 \times 11}{11 \times 4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3}{4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3}{4} ÷ \dfrac{5}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3}{4} \times \dfrac{4}{5} \times \dfrac{5}{3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - \dfrac{3 \times 4 \times 5}{4 \times 5 \times 3} + \dfrac{1}{3}\\[1em] \Rightarrow 3\dfrac{2}{3} - 1 + \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{11}{3} + \dfrac{1}{3} - 1\\[1em] \Rightarrow \dfrac{11 + 1}{3} - 1\\[1em] \Rightarrow \dfrac{12}{3} - 1\\[1em] \Rightarrow 4 - 1\\[1em] \Rightarrow 3

Hence, 323−3113\dfrac{2}{3} - \dfrac{3}{11} of 234÷114×123+13=32\dfrac{3}{4} ÷ 1\dfrac{1}{4} \times 1\dfrac{2}{3} + \dfrac{1}{3} = 3.

Question 6

Simplify :

2272\dfrac{2}{7} of 1534×214÷4715\dfrac{3}{4} \times 2\dfrac{1}{4} ÷ \dfrac{4}{7} of 2582\dfrac{5}{8}

Answer

⇒(227 of 1534)×214÷(47 of 258)⇒167×634×214÷47×218⇒16×637×4×214÷4×217×8⇒4×9×214÷32⇒36×214÷32⇒36×214×23⇒36×94×23⇒36×32⇒18×3⇒54.\Rightarrow \Big(2\dfrac{2}{7} \text{ of } 15\dfrac{3}{4}\Big) \times 2\dfrac{1}{4} ÷ \Big(\dfrac{4}{7} \text{ of } 2\dfrac{5}{8}\Big)\\[1em] \Rightarrow \dfrac{16}{7} \times \dfrac{63}{4} \times 2\dfrac{1}{4} ÷ \dfrac{4}{7} \times \dfrac{21}{8}\\[1em] \Rightarrow \dfrac{16 \times 63}{7 \times 4} \times 2\dfrac{1}{4} ÷ \dfrac{4 \times 21}{7 \times 8} \\[1em] \Rightarrow 4 \times 9 \times 2\dfrac{1}{4} ÷ \dfrac{3}{2} \\[1em] \Rightarrow 36 \times 2\dfrac{1}{4} ÷ \dfrac{3}{2} \\[1em] \Rightarrow 36 \times 2\dfrac{1}{4} \times \dfrac{2}{3} \\[1em] \Rightarrow 36 \times \dfrac{9}{4} \times \dfrac{2}{3} \\[1em] \Rightarrow 36 \times \dfrac{3}{2} \\[1em] \Rightarrow 18 \times 3 \\[1em] \Rightarrow 54.

Hence, 2272\dfrac{2}{7} of 1534×214÷4715\dfrac{3}{4} \times 2\dfrac{1}{4} ÷ \dfrac{4}{7} of 258=542\dfrac{5}{8} = 54.

Question 7

Simplify :

1÷47−131 ÷ \dfrac{4}{7} - \dfrac{1}{3} of 334+12÷33\dfrac{3}{4} + \dfrac{1}{2} ÷ 3

Answer

⇒1÷47−(13 of 334)+12÷3⇒1÷47−(13×334)+12÷3⇒1÷47−13×154+12÷3⇒1÷47−1×153×4+12÷3⇒1÷47−1512+12÷3⇒1÷47−54+12÷3⇒1×74−54+12×13⇒74−54+1×12×3⇒74−54+16⇒7×34×3−5×34×3+1×26×2⇒2112−1512+212⇒21−15+212⇒21−1312⇒812⇒23\Rightarrow 1 ÷ \dfrac{4}{7} - \Big(\dfrac{1}{3} \text{ of } 3\dfrac{3}{4}\Big) + \dfrac{1}{2} ÷ 3\\[1em] \Rightarrow 1 ÷ \dfrac{4}{7} - \Big(\dfrac{1}{3} \times 3\dfrac{3}{4}\Big) + \dfrac{1}{2} ÷ 3\\[1em] \Rightarrow 1 ÷ \dfrac{4}{7} - \dfrac{1}{3} \times \dfrac{15}{4} + \dfrac{1}{2} ÷ 3\\[1em] \Rightarrow 1 ÷ \dfrac{4}{7} - \dfrac{1 \times 15}{3 \times 4} + \dfrac{1}{2} ÷ 3\\[1em] \Rightarrow 1 ÷ \dfrac{4}{7} - \dfrac{15}{12} + \dfrac{1}{2} ÷ 3\\[1em] \Rightarrow 1 ÷ \dfrac{4}{7} - \dfrac{5}{4} + \dfrac{1}{2} ÷ 3\\[1em] \Rightarrow 1 \times \dfrac{7}{4} - \dfrac{5}{4} + \dfrac{1}{2} \times \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{7}{4} - \dfrac{5}{4} + \dfrac{1 \times 1}{2 \times 3}\\[1em] \Rightarrow \dfrac{7}{4} - \dfrac{5}{4} + \dfrac{1}{6}\\[1em] \Rightarrow \dfrac{7 \times 3}{4 \times 3} - \dfrac{5 \times 3}{4 \times 3} + \dfrac{1 \times 2}{6 \times 2}\\[1em] \Rightarrow \dfrac{21}{12} - \dfrac{15}{12} + \dfrac{2}{12}\\[1em] \Rightarrow \dfrac{21 - 15 + 2}{12}\\[1em] \Rightarrow \dfrac{21 - 13}{12}\\[1em] \Rightarrow \dfrac{8}{12}\\[1em] \Rightarrow \dfrac{2}{3}

Hence, 1÷47−131 ÷ \dfrac{4}{7} - \dfrac{1}{3} of 334+12÷3=233\dfrac{3}{4} + \dfrac{1}{2} ÷ 3 = \dfrac{2}{3}.

Question 8

Simplify :

(23+49)\Big(\dfrac{2}{3} + \dfrac{4}{9}\Big) of 35÷123×114−13\dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}

Answer

⇒(23+49) of 35÷123×114−13⇒(2×33×3+49) of 35÷123×114−13⇒(69+49) of 35÷123×114−13⇒(6+49) of 35÷123×114−13⇒109×35÷123×114−13⇒10×39×5÷123×114−13⇒3045÷123×114−13⇒23÷123×114−13⇒23÷53×54−13⇒23×35×54−13⇒2×3×53×5×4−13⇒2×3×53×5×4−13⇒24−13⇒12−13⇒1×32×3−1×23×2⇒36−26⇒3−26⇒16\Rightarrow \Big(\dfrac{2}{3} + \dfrac{4}{9}\Big) \text{ of } \dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \Big(\dfrac{2 \times 3}{3 \times 3} + \dfrac{4}{9}\Big) \text{ of } \dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \Big(\dfrac{6}{9} + \dfrac{4}{9}\Big) \text{ of } \dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \Big(\dfrac{6 + 4}{9}\Big) \text{ of } \dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{10}{9} \times \dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{10 \times 3}{9 \times 5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{30}{45} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{2}{3} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{2}{3} ÷ \dfrac{5}{3} \times \dfrac{5}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{2}{3} \times \dfrac{3}{5} \times \dfrac{5}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{2 \times 3 \times 5}{3 \times 5 \times 4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{2 \times \cancel{3} \times \cancel{5}}{\cancel{3} \times \cancel{5} \times 4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{2}{4} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{1}{2} - \dfrac{1}{3}\\[1em] \Rightarrow \dfrac{1 \times 3}{2 \times 3} - \dfrac{1 \times 2}{3 \times 2}\\[1em] \Rightarrow \dfrac{3}{6} - \dfrac{2}{6}\\[1em] \Rightarrow \dfrac{3 - 2}{6}\\[1em] \Rightarrow \dfrac{1}{6}

Hence, (23+49)\Big(\dfrac{2}{3} + \dfrac{4}{9}\Big) of 35÷123×114−13=16\dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3} = \dfrac{1}{6}

Question 9

Simplify :

(1415÷116+710)×34\Big(\dfrac{14}{15} ÷ 1\dfrac{1}{6} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}

Answer

⇒(1415÷116+710)×34⇒(1415÷76+710)×34⇒(1415×67+710)×34⇒(14×615×7+710)×34⇒(84105+710)×34⇒(45+710)×34⇒(4×25×2+710)×34⇒(810+710)×34⇒(8+710)×34⇒1510×34⇒15×310×4⇒4540⇒98⇒118\Rightarrow \Big(\dfrac{14}{15} ÷ 1\dfrac{1}{6} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{14}{15} ÷ \dfrac{7}{6} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{14}{15} \times \dfrac{6}{7} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{14 \times 6}{15 \times 7} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{84}{105} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{4}{5} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{4 \times 2}{5 \times 2} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{8}{10} + \dfrac{7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \Big(\dfrac{8 + 7}{10}\Big) \times \dfrac{3}{4}\\[1em] \Rightarrow \dfrac{15}{10} \times \dfrac{3}{4}\\[1em] \Rightarrow \dfrac{15 \times 3}{10 \times 4}\\[1em] \Rightarrow \dfrac{45}{40}\\[1em] \Rightarrow \dfrac{9}{8}\\[1em] \Rightarrow 1\dfrac{1}{8}

Hence, (1415÷116+710)×34=118\Big(\dfrac{14}{15} ÷ 1\dfrac{1}{6} + \dfrac{7}{10}\Big) \times \dfrac{3}{4} = 1\dfrac{1}{8}

Question 10

Simplify :

13(212+313)÷29(318−1112)\dfrac{1}{3}\Big(2\dfrac{1}{2} + 3\dfrac{1}{3}\Big) ÷ \dfrac{2}{9}\Big(3\dfrac{1}{8} - 1\dfrac{1}{12}\Big)

Answer

⇒13(212+313)÷29(318−1112)⇒13(52+103)÷29(258−1312)⇒13(5×32×3+10×23×2)÷29(25×38×3−13×212×2)⇒13(156+206)÷29(7524−2624)⇒13(15+206)÷29(75−2624)⇒13(356)÷29(4924)⇒35×16×3÷49×224×9⇒3518÷98216⇒3518×21698⇒3598×21618⇒514×12⇒6014⇒307⇒427\Rightarrow \dfrac{1}{3}\Big(2\dfrac{1}{2} + 3\dfrac{1}{3}\Big) ÷ \dfrac{2}{9}\Big(3\dfrac{1}{8} - 1\dfrac{1}{12}\Big)\\[1em] \Rightarrow \dfrac{1}{3}\Big(\dfrac{5}{2} + \dfrac{10}{3}\Big) ÷ \dfrac{2}{9}\Big(\dfrac{25}{8} - \dfrac{13}{12}\Big)\\[1em] \Rightarrow \dfrac{1}{3}\Big(\dfrac{5 \times 3}{2 \times 3} + \dfrac{10 \times 2}{3 \times 2}\Big) ÷ \dfrac{2}{9}\Big(\dfrac{25 \times 3}{8 \times 3} - \dfrac{13 \times 2}{12 \times 2}\Big)\\[1em] \Rightarrow \dfrac{1}{3}\Big(\dfrac{15}{6} + \dfrac{20}{6}\Big) ÷ \dfrac{2}{9}\Big(\dfrac{75}{24} - \dfrac{26}{24}\Big)\\[1em] \Rightarrow \dfrac{1}{3}\Big(\dfrac{15 + 20}{6}\Big) ÷ \dfrac{2}{9}\Big(\dfrac{75 - 26}{24}\Big)\\[1em] \Rightarrow \dfrac{1}{3}\Big(\dfrac{35}{6}\Big) ÷ \dfrac{2}{9}\Big(\dfrac{49}{24}\Big)\\[1em] \Rightarrow \dfrac{35 \times 1}{6 \times 3} ÷ \dfrac{49 \times 2}{24 \times 9}\\[1em] \Rightarrow \dfrac{35}{18} ÷ \dfrac{98}{216}\\[1em] \Rightarrow \dfrac{35}{18} \times \dfrac{216}{98}\\[1em] \Rightarrow \dfrac{35}{98} \times \dfrac{216}{18} \\[1em] \Rightarrow \dfrac{5}{14} \times 12 \\[1em] \Rightarrow \dfrac{60}{14}\\[1em] \Rightarrow \dfrac{30}{7} \\[1em] \Rightarrow 4\dfrac{2}{7}

Hence, 13(212+313)÷29(318−1112)=427\dfrac{1}{3}\Big(2\dfrac{1}{2} + 3\dfrac{1}{3}\Big) ÷ \dfrac{2}{9}\Big(3\dfrac{1}{8} - 1\dfrac{1}{12}\Big) = 4\dfrac{2}{7}.

Question 11

Simplify :

(14−19)÷(12+14÷13)\Big(\dfrac{1}{4} - \dfrac{1}{9}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{1}{4} ÷ \dfrac{1}{3}\Big)

Answer

⇒(14−19)÷(12+14÷13)⇒(1×94×9−1×49×4)÷(12+14×31)⇒(936−436)÷(12+1×34×1)⇒(9−436)÷(12+34)⇒(536)÷(12+34)⇒(536)÷(1×22×2+34)⇒(536)÷(24+34)⇒(536)÷(2+34)⇒(536)÷(54)⇒536×45⇒5×436×5⇒436⇒19.\Rightarrow \Big(\dfrac{1}{4} - \dfrac{1}{9}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{1}{4} ÷ \dfrac{1}{3}\Big)\\[1em] \Rightarrow \Big(\dfrac{1 \times 9}{4 \times 9} - \dfrac{1 \times 4}{9 \times 4}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{1}{4} \times \dfrac{3}{1}\Big)\\[1em] \Rightarrow \Big(\dfrac{9}{36} - \dfrac{4}{36}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{1 \times 3}{4 \times 1}\Big)\\[1em] \Rightarrow \Big(\dfrac{9 - 4}{36}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{3}{4}\Big)\\[1em] \Rightarrow \Big(\dfrac{5}{36}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{3}{4}\Big)\\[1em] \Rightarrow \Big(\dfrac{5}{36}\Big) ÷ \Big(\dfrac{1 \times 2}{2\times 2} + \dfrac{3}{4}\Big)\\[1em] \Rightarrow \Big(\dfrac{5}{36}\Big) ÷ \Big(\dfrac{2}{4} + \dfrac{3}{4}\Big)\\[1em] \Rightarrow \Big(\dfrac{5}{36}\Big) ÷ \Big(\dfrac{2 + 3}{4}\Big)\\[1em] \Rightarrow \Big(\dfrac{5}{36}\Big) ÷ \Big(\dfrac{5}{4}\Big)\\[1em] \Rightarrow \dfrac{5}{36} \times \dfrac{4}{5}\\[1em] \Rightarrow \dfrac{5 \times 4}{36 \times 5}\\[1em] \Rightarrow \dfrac{4}{36}\\[1em] \Rightarrow \dfrac{1}{9}.

Hence, (14−19)÷(12+14÷13)=19\Big(\dfrac{1}{4} - \dfrac{1}{9}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{1}{4} ÷ \dfrac{1}{3}\Big) = \dfrac{1}{9}.

Question 12

Simplify :

378−{138÷(245−1710)}3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(2\dfrac{4}{5} - 1\dfrac{7}{10}\Big)\right\rbrace

Answer

⇒378−{138÷(245−1710)}⇒378−{138÷(145−1710)}⇒378−{138÷(14×25×2−1710)}⇒378−{138÷(2810−1710)}⇒378−{138÷(28−1710)}⇒378−{138÷(1110)}⇒378−{118÷1110}⇒378−{118×1011}⇒378−108⇒318−108⇒31−108⇒218⇒258\Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(2\dfrac{4}{5} - 1\dfrac{7}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{14}{5} - \dfrac{17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{14 \times 2}{5 \times 2} - \dfrac{17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{28}{10} - \dfrac{17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{28 - 17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{11}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace\dfrac{11}{8} \div \dfrac{11}{10}\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace\dfrac{11}{8} \times \dfrac{10}{11}\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \dfrac{10}{8}\\[1em] \Rightarrow \dfrac{31}{8} - \dfrac{10}{8}\\[1em] \Rightarrow \dfrac{31 - 10}{8}\\[1em] \Rightarrow \dfrac{21}{8}\\[1em] \Rightarrow 2\dfrac{5}{8}

Hence, 378−{138÷(245−1710)}=2583\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(2\dfrac{4}{5} - 1\dfrac{7}{10}\Big)\right\rbrace = 2\dfrac{5}{8}.

Question 13

Simplify :

3÷[3×{3−(3−14)}]3 \div \Big[3\times \left\lbrace3 - \Big(3 - \dfrac{1}{4}\Big)\right\rbrace \Big]

Answer

⇒3÷[3×{3−(3−14)}]⇒3÷[3×{3−(31−14)}]⇒3÷[3×{3−(3×41×4−14)}]⇒3÷[3×{3−(124−14)}]⇒3÷[3×{3−(12−14)}]⇒3÷[3×{3−(114)}]⇒3÷[3×{31−114}]⇒3÷[3×{3×41×4−114}]⇒3÷[3×{124−114}]⇒3÷[3×{12−114}]⇒3÷[3×{14}]⇒3÷[3×14]⇒3÷34⇒3×43⇒4×33⇒4\Rightarrow 3 \div \Big[3\times \left\lbrace3 - \Big(3 - \dfrac{1}{4}\Big)\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace3 - \Big(\dfrac{3}{1} - \dfrac{1}{4}\Big)\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace3 - \Big(\dfrac{3 \times 4}{1 \times 4} - \dfrac{1}{4}\Big)\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace3 - \Big(\dfrac{12}{4} - \dfrac{1}{4}\Big)\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace3 - \Big(\dfrac{12 - 1}{4}\Big)\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace3 - \Big(\dfrac{11}{4}\Big)\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace\dfrac{3}{1} - \dfrac{11}{4}\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace\dfrac{3 \times 4}{1 \times 4} - \dfrac{11}{4}\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace\dfrac{12}{4} - \dfrac{11}{4}\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace\dfrac{12 - 11}{4}\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[3\times \left\lbrace\dfrac{1}{4}\right\rbrace \Big]\\[1em] \Rightarrow 3 \div \Big[\dfrac{3 \times 1}{4} \Big]\\[1em] \Rightarrow 3 \div \dfrac{3}{4}\\[1em] \Rightarrow 3 \times \dfrac{4}{3}\\[1em] \Rightarrow \dfrac{4 \times 3}{3}\\[1em] \Rightarrow 4

Hence, 3÷[3×{3−(3−14)}]=43 \div \Big[3\times \left\lbrace3 - \Big(3 - \dfrac{1}{4}\Big)\right\rbrace \Big] = 4.

Question 14

Simplify :

513−[213÷{34−12×(710−35)}]5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{2} \times \Big(\dfrac{7}{10} - \dfrac{3}{5}\Big)\right\rbrace\Big]

Answer

⇒513−[213÷{34−12×(710−35)}]⇒513−[213÷{34−12×(710−3×25×2)}]⇒513−[213÷{34−12×(710−610)}]⇒513−[213÷{34−12×(7−610)}]⇒513−[213÷{34−12×110}]⇒513−[213÷{34−1×12×10}]⇒513−[213÷{34−120}]⇒513−[213÷{3×54×5−120}]⇒513−[213÷{1520−120}]⇒513−[213÷{15−120}]⇒513−[213÷{1420}]⇒513−[73÷1420]⇒513−[73×2014]⇒513−[7×203×14]⇒513−[14042]⇒163−103⇒16−103⇒63⇒2\Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{2} \times \Big(\dfrac{7}{10} - \dfrac{3}{5}\Big)\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{2} \times \Big(\dfrac{7}{10} - \dfrac{3 \times 2}{5 \times 2}\Big)\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{2} \times \Big(\dfrac{7}{10} - \dfrac{6}{10}\Big)\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{2} \times \Big(\dfrac{7 - 6}{10}\Big)\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{2} \times \dfrac{1}{10}\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1 \times 1}{2 \times 10}\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{20}\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3 \times 5}{4 \times 5} - \dfrac{1}{20}\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{15}{20} - \dfrac{1}{20}\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{15 - 1}{20}\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{14}{20}\right\rbrace\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[\dfrac{7}{3} \div \dfrac{14}{20}\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[\dfrac{7}{3} \times \dfrac{20}{14}\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[\dfrac{7 \times 20}{3 \times 14}\Big]\\[1em] \Rightarrow 5\dfrac{1}{3} - \Big[\dfrac{140}{42}\Big]\\[1em] \Rightarrow \dfrac{16}{3} - \dfrac{10}{3}\\[1em] \Rightarrow \dfrac{16 - 10}{3}\\[1em] \Rightarrow \dfrac{6}{3}\\[1em] \Rightarrow 2

Hence, 513−[213÷{34−12×(710−35)}]=25\dfrac{1}{3} - \Big[2\dfrac{1}{3} \div \left\lbrace\dfrac{3}{4} - \dfrac{1}{2} \times \Big(\dfrac{7}{10} - \dfrac{3}{5}\Big)\right\rbrace\Big] = 2.

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