A is 3 times as fast as B and is, therefore, able to complete a work in 32 days lesser than B. A and B, working together, can complete the work in _________.
Answer & explanation
Correct answer: option 2
Given,
A is 3 times as fast as B and is, therefore, able to complete a work in 32 days lesser than B.
A : B
Time 1 : 3
Efficiency 3 : 1
⇒ 2T = 32 days,
⇒ T = 16 days,
⇒ Total work = 3 x 16 = 48 units, ..(Efficiency × Days = Total work)
⇒ A + B can complete the work in = \(\frac{48}{(3+1)}\) = \(\frac{48}{(4)}\) = 12 days. ..(\(\frac{Work}{Efficiency}\) = Time)