Based on the information that has been given in the question, the minutes that the slower pipe alone can use in filling the tank can be denoted by y minutes.
Therefore, the faster pipe will fill it in 1/3 × x = x/3 minutes.
Therefore,
1/x + 3/x = 1/36
4/x = 1/36
x = 36 × 4
x = 144
The number of minutes taken by the slower pipe will be 144 minutes.
