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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

18×401×4084085\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}

411×425411×22545×221145×285135.\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}

135×61485×2548×255×42002010.\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

34×134×100 paise3×1004 paise3004 paise75 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 km58×1000 m5×10008 m50008 m625 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 hour512×60 min5×6012 min30012 min25 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÷159×31376÷149×10376×914×103714×93×10612×3×5352212.\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+11943÷(37×218)+10943÷3×217×8+10943÷6356+10943÷98+10943×89+1094×83×9+1093227+1093227+10×39×33227+302732+302762272827\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÷14615÷(3110×52)÷14615÷31×510×2÷14615÷15520÷14(615÷314)÷14(315÷314)÷14(315×431)÷1445÷1445×4165315.\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 :

3233113\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

323311 of 234÷114×123+13323311×234÷114×123+13323311×114÷114×123+133233×1111×4÷114×123+133233×1111×4÷114×123+1332334÷114×123+1332334÷54×123+1332334×45×53+133233×4×54×5×3+133231+13113+13111+1311231413\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, 3233113\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÷47×21816×637×4×214÷4×217×84×9×214÷3236×214÷3236×214×2336×94×2336×3218×354.\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÷47131 ÷ \dfrac{4}{7} - \dfrac{1}{3} of 334+12÷33\dfrac{3}{4} + \dfrac{1}{2} ÷ 3

Answer

1÷47(13 of 334)+12÷31÷47(13×334)+12÷31÷4713×154+12÷31÷471×153×4+12÷31÷471512+12÷31÷4754+12÷31×7454+12×137454+1×12×37454+167×34×35×34×3+1×26×221121512+2122115+21221131281223\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÷47131 ÷ \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÷123×11413\dfrac{3}{5} ÷ 1\dfrac{2}{3} \times 1\dfrac{1}{4} - \dfrac{1}{3}

Answer

(23+49) of 35÷123×11413(2×33×3+49) of 35÷123×11413(69+49) of 35÷123×11413(6+49) of 35÷123×11413109×35÷123×1141310×39×5÷123×114133045÷123×1141323÷123×1141323÷53×541323×35×54132×3×53×5×4132×3×53×5×413241312131×32×31×23×2362632616\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÷123×11413=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)×341510×3415×310×4454098118\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(3181112)\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(3181112)13(52+103)÷29(2581312)13(5×32×3+10×23×2)÷29(25×38×313×212×2)13(156+206)÷29(75242624)13(15+206)÷29(752624)13(356)÷29(4924)35×16×3÷49×224×93518÷982163518×216983598×21618514×126014307427\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(3181112)=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 :

(1419)÷(12+14÷13)\Big(\dfrac{1}{4} - \dfrac{1}{9}\Big) ÷ \Big(\dfrac{1}{2} + \dfrac{1}{4} ÷ \dfrac{1}{3}\Big)

Answer

(1419)÷(12+14÷13)(1×94×91×49×4)÷(12+14×31)(936436)÷(12+1×34×1)(9436)÷(12+34)(536)÷(12+34)(536)÷(1×22×2+34)(536)÷(24+34)(536)÷(2+34)(536)÷(54)536×455×436×543619.\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, (1419)÷(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÷(2451710)}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÷(2451710)}378{138÷(1451710)}378{138÷(14×25×21710)}378{138÷(28101710)}378{138÷(281710)}378{138÷(1110)}378{118÷1110}378{118×1011}37810831810831108218258\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÷(2451710)}=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(314)}]3 \div \Big[3\times \left\lbrace3 - \Big(3 - \dfrac{1}{4}\Big)\right\rbrace \Big]

Answer

3÷[3×{3(314)}]3÷[3×{3(3114)}]3÷[3×{3(3×41×414)}]3÷[3×{3(12414)}]3÷[3×{3(1214)}]3÷[3×{3(114)}]3÷[3×{31114}]3÷[3×{3×41×4114}]3÷[3×{124114}]3÷[3×{12114}]3÷[3×{14}]3÷[3×14]3÷343×434×334\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(314)}]=43 \div \Big[3\times \left\lbrace3 - \Big(3 - \dfrac{1}{4}\Big)\right\rbrace \Big] = 4.

Question 14

Simplify :

513[213÷{3412×(71035)}]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÷{3412×(71035)}]513[213÷{3412×(7103×25×2)}]513[213÷{3412×(710610)}]513[213÷{3412×(7610)}]513[213÷{3412×110}]513[213÷{341×12×10}]513[213÷{34120}]513[213÷{3×54×5120}]513[213÷{1520120}]513[213÷{15120}]513[213÷{1420}]513[73÷1420]513[73×2014]513[7×203×14]513[14042]16310316103632\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÷{3412×(71035)}]=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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