Ten men or twelve women can finish the same work in 10 days. If 5 men and 2 women undertake the work together, how many days will they take to complete the work?

15

10M = 12W = 10 days,

Therefore, M : W = 12 : 10 = 6 : 5 (Efficiency)

⇒ Total work = 12(5) x 10 = 60 x 10 = 600 units   ..(Efficiency × Days = Total work)

⇒ Time required by 5M and 2W to complete the work = \(\frac{600}{5(6)+2(5)}\) = \(\frac{600}{40}\) = 15 days.   ..(\(\frac{Work}{Efficiency}\) = Time)