Question

1 and 2 half of the work in 5 days and B can do 2 by 5 of the work in 10 days in how many days both A and B together can do the work

Answer 1

A can do 1/3 of the work in 5 days So for total work A will take 5÷(1/3) =5×3= 15 days.

B can do 2/5 of the work in 10 days. So for total work B will take 10÷(2/5) = 25 days.

So now its simple that A can do the work in 15 days and B in 25 days.

LCM of 15 and 25 is 75.

So lets take total work to be 75 units.

A = 75/15 = 5 units/day

B = 75/25 = 3 units/day

So together, A + B = 5 +3 = 8 units/day

So for 75 units of work, time taken by them together will be 75/8 = 9.375 days.