Three pipes A, B and C can fill a cistern in 12, 18 and 24 minutes respectively. If all the pipes are opened for 4 minutes, then what fraction of the water left to be filled.
Answer & explanation
Correct answer: option 2
Now total efficiency = 6 + 4 +3 = 13
In 4 minutes tank filled = 13 × 4 = 52 ltr
Remaining part of tank = 72 - 52 = 20
Fraction of part left to be filled = \(\frac{20}{72}\) = \(\frac{5}{18}\)