A and B together can do a piece of work in 21 days. B and C together can do it in 24 days. A and C together can do it in 33 days. In how many days will A, B, and C finish it together?
Show answer & explanation
Correct answer: A
Explanation
The Correct answer is option 1 i.e. 17 days
A and B together can do a piece of work in 21 days
B and C together can do it in 24 days
A and C together can do it in 33 days
Total work = LCM ( 21, 24, 33) = 1848
The efficiency of A and B = 1848/21 = 88
The efficiency of B and C = 1848/24 = 77
The efficiency of C and A = 1848/33 = 56
Thus,
The efficiency of A, B, and C = (88 +77 + 56)/2 = 110.5
Hence,
A, B, and C will finish it together = 1848/110.5 = 16.73 ≈ 17 days