SSC CPO SI and ASI Model Paper 6

(4) Assume that A can complete thework in x days; then, B cancomplete the same work in 3x days.
If A takes x days,
B takes 3x days = x + 2x days= x + 30 days
∴ 2x = 30 or x = 15 days
It means that A takes 15 days tocomplete the work alone, whereasB takes 45 days for the same.
A's one-day work $=\frac{1}{15}$B's one-day work $=\frac{1}{45}$
A and B's one-day work $=\frac{4}{45}$
∴ A and B together can completethe work in $\frac{45}{4}=11.25$days