Question

20 women can do a job in 6 days. in how many days can 25 women do the same job

Answer 1

Step-by-step explanation:

If 6 men can complete a work in 15 days. It means the work needs 90 man-days for its completion. So 1 man does 1/90th of the work in a day, and 7 men can do 7/90th of the work in a day.

If 10 women can complete a work in 15 days. It means the work needs 150 woman-days for its completion. So 1 woman does 1/150th of the work in a day, and 5 women can do 5/150th or 1/30th of the work in a day.

So 7 men and 5 women can do (7/90)+(1/30) = (7/90)+(3/90) = 10/90 = 1/9th of the work in a day. So they will complete the work in 9 days.

Answer 2

While solving such questions, equating the TOTAL WORK is the first step.

6 Men working 15 days complete the work. So, TOTAL WORK = 90 Mandays = 90 MD

10 Women complete the same work in 15 days. So, TOTAL WORK = 150 Womandays = 150 WD

So, 90 MD = 150 WD. Or, 1 WD = 3535 MD = 0.6 MD ….. Eqn(1)

Now, 7 Men and 5 Women are equivalent as (7+0.6×5)(7+0.6×5) Men = 10 Men.

Work done by 10 Men in one day is 10 MD.

So, time taken to complete the Work can be calculated as:

TOTAL TIME = 90MD10MD90MD10MD = 9 Days (Answer)

I HOPE IT'S HELPFUL for you