A started a work and left after working 4 days. B finished the remaining work in next 18 days. If A left the work after working 6 days, then B would have finished the remaining work in 12 days. Find in how many days A and B alone can complete the work.
Answer & explanation
Correct answer: option 2
ATQ, If A works for 2 extra day then B finish the work 6 days earlier.
2 days of A's work = 6 days of B's work
Efficiency ratio = A : B = 6 : 2 = 3 : 1
Total work = No. of days × efficiency
= (3 x 4) + (1 x 18) = 30 (according to 1st condition)
A alone will finish the work in = \(\frac{30}{3}\) = 10 days
B alone will finish the work in = \(\frac{30}{1}\) = 30 days