Answer:
Time taken for pump B to empty pool = 1 hour.
Step-by-step explanation:
Given:
Time taken for pump A to empty pool = 4 hour
Time taken together = 48 minutes = 48 / 60 = 4/5 hour
Find:
Time taken for pump B to empty pool
Computation:
Assume;
Time taken for pump B to empty pool = a
1/4 + 1/a = 1 / (4/5)
1/4 + 1/a = 5/4
1/a = 5/4 - 1/4
1/a = (5 - 1) / 4
1/a = 1
a = 1
Time taken for pump B to empty pool = 1 hour.