Question

A can do 1/2 of the work in 5 days and B can do 2/5 of the work in 10 days .In how many days both A and B together can do the work? a) 51/7 days. b) 50/7 days. c) 52/7 days. d) 54/7 days. e) none of these​

Answer 1

Step-by-step explanation:

A can do 1/2 of the work in 5 days then A can do the complete work in 5/1/2 days => 10 days. B can do 2/5of the work in 10 days so B can do the complete work in 10/(2/5) => 25 days. So A and B can do the complete work in 1/(1/25+ 1/10) days =>

1/(10+25/350) days => 250/35 days => 50/7 days. So the correct option is (b) 50/7 days. Hope it helps you.