Question

a river is rising at a rate of 3 inches per hour. If the river rises more than 2 feet then it will exceeed flood stage. How long long can the river rise at the rate without exceeding flood stage? ...?

Answer 1

There are several information's already given in the question. Based on those given information's, the answer can be easily deduced.

1 feet = 12 inches
Then
2 feet = 24 inches
It is already given that
Time taken by the river to rise 3 inches = 1 hour
Then
Time taken by the river to rise 24 inches = 24/3
                                                                 = 8 hours
The river can continue to rise up to 8 hours without exceeding the flood stage. I hope that the procedure is clear enough for you to understand.

Answer 2

The can continue to rise at this same rate for a total of eight hours
Hope this helps !