6 men or 10 women can reap a field in 15 days, then the number of days that 12 men and 5 women will take to reap the same field is :

Work done by 6 men = work done by 10 women. Work done by 1 man = work done by 10 / 6 = 5/3 women ∴ 12 men + 5 women = 12 x ( 5 / 3) + 5 = 25 women ∴ W1 x D 1 = W2 x D2 W = women, D=days 10 X 15 = 25 x D2 D2 = 6