Question

A submarine is 105 feet below the surface of the water, and it begins to ascend at a rate of 3 feet per minute. After how many minutes will the submarine be 81 feet below the surface?

Answer 1

8 minutes

Explanation:

Step one:

given

A submarine is 105 feet below the surface of the water

depth of submarine= 105 feet

let the time of ascending be x

Required

The time taken to ascend up to 81 ft

Step two:

the expression for the situation is

81=105-3x

solve for x

3x=105-81

3x=24

divide both sides by 3

x= 24/3

x=8 minutes