Answer: First, we need to calculate how many inches the coin will sink in 1 second:
1/5 inch per second x 1 second = 1/5 inch
Next, we can multiply the sinking rate by the number of seconds to find the total distance the coin will sink:
1/5 inch x 7.5 seconds = 1.5 inches
Therefore, the coin will sink 1.5 inches in 7 1/2 seconds.
Explanation: