The scuba diver must descend 3 feet in the fifth minute to meet the goal.
Why?
To find how many feet does the scuba diver need to descend to reach the goal of 35 feet in 5 minutes, we need to calculate how many feet he did descend on the first 4 minutes.
So, calculating we have:
Hence, we can see that at the 4 minute, he has only descended 32ft. It means that he need to descend 3 feet more in the fifth minute.
Have a nice day!