Answer: diver's descent rate is 7/15 feet per second.
Explanation:
Given that the diver descends 3 1/2 feet in 7 1/2 seconds, let's convert the mixed numbers to improper fractions for ease of calculation:
3 1/2 feet = 7/2 feet
7 1/2 seconds = 15/2 seconds
Now, let's calculate the descent rate:
Descent Rate = (7/2 feet) ÷ (15/2 seconds)
To divide by a fraction, you multiply by its reciprocal:
Descent Rate = (7/2 feet) * (2/15 seconds)
Descent Rate = (7 * 2) / (2 * 15) feet/second
Descent Rate = 14/30 feet/second
Descent Rate = 7/15 feet/second
Therefore, the diver's descent rate is 7/15 feet per second.