Question

00 The ratio of work done by (x + 2) men in (x-2) days to that of (x-1) men in (x + 1) days is 4: 5, the value of xis
(A) +_4
(B) 6
(C) 4
(D) 8​

Answer 1

Answer:

C

Let a man done y work in a day .

So x+2 man ' s work in x-2 days = y(x+2)(x-2)

Similarly other.

$\frac{y(x + 2)(x - 2)}{y(x + 1)(x - 1)} = \frac{4}{5} \\ \\ 5( {x}^{2} - 4) = 4( {x}^{2} - 1) \\ \\ 5 {x}^{2} - 20 = 4 {x}^{2} - 4 \\ \\ {x}^{2} = 16 \\ x = 4$

Number of men or days can't be negative