Question

30 men can reap the rice of 20 hectares of field in 6 days. How, long will it take for 40 men to
reap the rice of 90 hectares of field ?​

Answer 1

Answer:

$20\frac{1}{4}$ days

Step-by-step explanation:

30 men can reap the rice of 20 hectares of field in 6 days.

If men (M) are increased, number of days (D) required will decrease.

This means that Number of men (M) and number of days (D) required are inversely proportional.  $\frac{M1}{M2} = \frac{D2}{D1}$

Now If Area of field (A) to be reaped is increased, number of days (D) required will be increased.

This means that Area of field (A) to be reaped and number of days (D) required are directly proportional.  $\frac{M1}{M2} = \frac{A1}{A2}$

∴ $\frac{M1 . D1}{A1} = \frac{M2 . D2}{A2}$

∴ $\frac{30 . 6}{20} = \frac{40 . D2}{90}$

∴ $D2 = \frac{30 . 6 . 90}{20 . 40}$ $= \frac{81}{4} = 20\frac{1}{4}$