Final answer:
To calculate the total distance, add the initial 4 miles you drove to the distance your friend covered, which was 75 miles in 15 minutes at a rate of 1.25 miles per 15 seconds, resulting in a combined total of 79 miles.
Step-by-step explanation:
The question asks us to calculate the total distance covered when initially you drive a boat for 4 miles and then let a friend drive it at a rate of 1.25 miles per 15 seconds for 15 minutes.
Step-by-Step Calculation:
- First, we note the initial distance covered by you, which is 4 miles.
- Next, we need to calculate the distance your friend covers in 15 minutes at the given rate. Since there are 60 seconds in a minute, 15 minutes is equal to 15 x 60 = 900 seconds.
- We need to find out how many 15-second intervals are in 900 seconds. This is 900 / 15 = 60 intervals.
- Since your friend covers 1.25 miles in each 15-second interval, over 60 intervals your friend would cover 1.25 miles x 60 = 75 miles.
- Add the distance you covered to the distance covered by your friend to obtain the total distance. This is 4 miles + 75 miles = 79 miles.
Therefore, the total combined distance you and your friend cover is 79 miles.