Pipe L can fill a pool in 30 hours and pipe M in 45 hours. If both the pipes are opened in an empty pool, how much time will they take to fill it?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 18 hours.
Pipe L can fill a pool in 30 hours and pipe M in 45 hours
L.C.M(30, 45) = 90
The efficiency of Pipe L = 90/30 = 3 units
The efficiency of Pipe M = 90/45 = 2 units
Time taken by both the pipes = 90/(3 + 2)
⇒ 90/5 = 18 hours