Correct Answer - Option 4 : 50 min
Given:
A can fill up the tank in 60 min
B can fill the tank in 75 min
C empties the tank in 100 min
Concept used:
Work = time × efficiency
Calculation:
Work |
Time |
Efficiency |
A |
60 mins |
300/60 = 5 |
B |
75 mins |
300/75 = 4 |
C |
100 mins |
300/100 = 3 |
work (LCM of time) |
300 units |
|
Efficiency of C = -3 as it is emptying the pipe.
Total efficiency of A, B ,and C together = 5 + 4 - 3 = 6
Time to fill the tank = 300/6
⇒ 50 mins
∴ Time taken to fill the tank is 50 mins.