Officer Aptitude Rating (OAR) Test 2025 – 400 Free Practice Questions to Pass the Exam

To determine how long it would take the slower pipe to fill the pool by itself, consider the rates at which both pipes fill the pool together and the relationship between their speeds. When both pipes together can fill the pool in five hours, this means their combined rate is 1 pool per 5 hours, or 0.2 pools per hour.

If we denote the faster pipe's filling time as 'x' hours, its rate would be 1/x pools per hour. For the slower pipe, which we wish to find the time for, we can denote its time as 'y' hours, giving it a rate of 1/y pools per hour.

The rates of the two pipes add together to equal the total rate of filling the pool. Therefore, we can set up the equation:

1/x + 1/y = 0.2

If we rearrange to solve for one of the variables and substitute, we would ultimately determine that the slower pipe fills at a rate that can be expressed in terms of 5 hours and the relative speeds of both pipes.

Through calculations involving their combined rate, it can be shown that if one pipe takes longer and is labeled as slower (while knowing the combined filling time), plugging in potential values