(4) 3 × 5 men + 7 × 5 women= 4 × 4 men + 6 × 4 women, ⇒15 men + 35 women = 16 men + 24 women, ⇒16 men – 15 men = 35 women – 24 women, ⇒1 man = 11 women, ⇒3 men = 33 women Since 3 men + 7 women = 5 days, hence, 40 women = 5 days Let time required by 10 women to finish the job be D days. 40 × 5 = 10 × D D = 20 days