A and B can complete a piece of work in 27 days and 54 days, respectively. They completed the work in 9 days with the help of C. How many days will C take to complete eight-ninths of the work alone?
Answer & explanation
Correct answer: option 1
A = 27 days, B = 54 days,
⇒ With the help of C, A + B can complete the work in 9 days = \(\frac{54}{2+1+C}\) = 9 days,
⇒ \(\frac{54}{3+C}\) = 9 days,
⇒ 54 = 27 + 9C
⇒ 27 = 9C
⇒ C = 3, (Efficiency)
⇒ Time required by C to complete 8/9th of the work = \(\frac{8/9 * 54}{3}\) = \(\frac{48}{3}\) = 16 days, ..(\(\frac{Work}{Efficiency}\) = Time)