5 men started working to complete a work in 15 days. After 5 days, 10 women are accompanied by to them to complete the work in next 5 days. If the work is to be done by women only, when could the work be over, if 10 women have started it?

According to the question,
5 men's 1 day's work = 1/15 .....(i)
∴ 5 men's 5 day's work = (1/15) x 5 = 1/3
∴ Remaining work = 1 - (1/3) = 2/3
5 men + 10 women can do 2/3 of the work in 5 days.
∴ 5 men + 10 women can do the whole of the work in 15/2 days.
∴ (5 men + 10 women's) 1 day's work = 2/15 .......(ii)
10 women 1 days work = (2/15) - 5 men's 1 day's work
= (2/15) - (1/15)
= 1/15
∴ 10 women can finish the work in 15 days