Question

a and b together finish a work in 30 days they worked for it 20 days and then b left the remaning work done by alone in 20 more days b alone can finish the work in

Answer 1

(a+b)20 +a(20)=1
1/30 ×20 +20a=1
2/3 +20a=1
20a=1-2/3
20a=3-2/3
20a=1/3
a=1/20×3
a=1/60
a+b=1/30
b=1/30-1/60
b=2-1/60
b=1/60
b can complete in 60 days