After visiting the Titanic, Captain Brain and Mr. Pinky are taking the Alvin submarine back to the surface of the water. After ascending for 7 hours, they are 1108 feet below the surface of the water. Then, at 9 hours they are 996 feet below the surface.

What is the rate of the submarine?   feet per hour

How far does it rise every 5 hours?   feet

What is its depth after 14 hours?   feet