Mathematics
The work done by (3x - 1) men in (2x + 3) days and the work done by (3x - 4) men in (2x + 1) days are in the ratio 4 : 3. Find the value of x.
Ratio Proportion
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Answer
Amount of work done by (3x - 1) men in (2x + 3) days = (3x - 1)(2x + 3),
Amount of work done by (3x - 4) men in (2x + 1) days = (3x - 4)(2x + 1)
According to question,
3(3x − 1)(2x + 3) = 4(3x - 4)(2x + 1)
3(6x2 + 9x − 2x − 3) = 4(6x2 + 3x − 8x − 4)
3(6x2 + 7x − 3) = 4(6x2 − 5x − 4)
18x2 + 21x − 9 = 24x2 − 20x − 16
18x2 − 24x2 + 21x + 20x − 9 + 16 = 0
−6x2 + 41x + 7 = 0
6x2 − 41x − 7 = 0
6x2 - 42x + x - 7 = 0
6x(x − 7) + 1(x − 7) = 0
(6x + 1)(x − 7) = 0
6x + 1 = 0 or x - 7 = 0
x = − or x = 7
x ≠ − as that will make number of men negative which is not possible.
Hence, value of x = 7.
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