Through the first pipe, the pool is filled in 6 hours, and through the second – in 14 hours. The first pipe worked for

Through the first pipe, the pool is filled in 6 hours, and through the second – in 14 hours. The first pipe worked for 1 hour, and the second for 7 hours. What part of the pool is left to fill?

Take the volume of the pool as 1 (unit). Fill in the table: filling rate, time (in hours), pool volume.

What is the filling rate of the pool with the 1st pipe: 1: 6 = 1/6 of the pool per hour.
What is the filling rate of the pool with the 2nd pipe: 1:14 = 1/14 of the pool per hour.
What part of the pool was filled by the 2nd pipe in 7 hours: 1/14 * 7 = 1/2 of the pool, which means that half is not yet filled.
1/2 – 1/6 = 3/6 – 1/6 = 2/6 = 1/3 of the pool left to fill.
Verification:

7: 14 = 1/2.
1: 6 = 1/6.
1/2 – 1/6 = 1/3.
Answer: 1/3 of the pool.