The ratio of efficiencies of A and B is 3 : 7, A takes 48 days more than B to complete a work. If they work together, in how many days, will the work be completed?
Answer & explanation
Correct answer: option 2
Time taken ∝ \(\frac{1}{efficiency}\)
A : B
ratio of efficiency 3 : 7
time taken 7 : 3 ⇒ difference 4R = 48
R = 12
Total work = (3 + 7) 12 = 120
Efficiency of A & B together = 10
Time taken by A and B = \(\frac{Total\; work}{Efficiency}\)
= \(\frac{120}{10}\) = 12 days