A can complete a certain work in 30 days. B is 25% more efficient than A and C is 20% more efficient than B. They all worked together for 3 days. B alone will complete the remaining work in:
Answer & explanation
Correct answer: option 4
A = 30 days,
Given,
B is 25% more efficient than A and C is 20% more efficient than B.
Therefore, A : B : C
Efficiency 4 : 5 : 6
⇒ Total work = 4 x 30 = 120 units ..(Efficiency × Days = Total work)
⇒ A + B + C worked for 3 days = (4 + 5 + 6) x 3 = (15) x 3 = 45 units.
⇒ Remaining work = 120 - 45 = 75 units.
⇒ Time required by B to complete 75 units = \(\frac{75}{5}\) = 15 days. ..(\(\frac{Work}{Efficiency}\) = Time)