If A alone can complete a work in 20 days and B alone can complete the same work in 30 days, then which of the following statement(s) is/are correct?
I. Ratio of efficiency of A and B is 3 : 2.
II. Working together A and B can complete the same work in 12 days.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Both I and II.
Total work = 60 (LCM 20 and 30)
Ratio of the efficiency of A and B = (60/20) : (60/30) = 3 : 2
Thus, Statement I is correct.
Total efficiency of A and B = 3 + 2 = 5 units/day
Time required for A and B to complete the work = 60/5 = 12 days
Thus, Statement II is correct.