Question

A submarine is at 40 feet below sea level. Then it moves up 10 feet. Find the depth of the submarine.​

Answer 1

Here, we have to denote the depth in feet.

Submarine is at a depth of 40ft, so it can be represented as a negative integer, -40ft.

It rises up by 10 ft, which can be represented by +10.

The current depth of the submarine = -40ft + 10 ft. = -30ft, which is the required answer.
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