Question

If 3 men or 4 women can do a piece of work in 43 days, how long will 7 men and 5 women take to do it.

Answer 1

3 Men or 4 Women can finish the work in 43 days, therefore, in one day 3 men or 4 women can finish 1/43 amount of the total work. Therefore, a man can finish 1/43 * 1/3 amount of work in a day and a woman can finish 1/43 * 1/4 amount of work in a day.

When 7 men and 5 women are working together, amount of work done in a day = 7 * (1/ 43) * (1/3) + 5 * (1/ 43) * (1/4) amount of work in a day.

= (1/43)* (7/3 + 5/4)

= (1/43)* (43 / 12)

= 1/12

So 7 men and 5 women finish 1/12 of the work in day. Hence, 7 men and 5 women can finish the entire work in 12 days.