Explanation:
The given data is,
The time required to fill the swimming pool using two pipes = 12 hours.
To fill the half of the pool,
The time for which the pipe of larger diameter is used = 4 hours.
The time for which the pipe of smaller diameter is used = 9 hours.
It is required to find the time that would take for each pipe to fill the pool separately.
Let the time taken by the larger pipe to fill the pool be x hours.
And, the time taken by the smaller pipe to fill the pool be y hours.
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