Question

Suppose a deep-sea diver dives from the surface to $81$ $feet$ below the surface.

He then dives down $13$ more $feet$.

The diver's depth is represented by the sum $-81+\left(-13\right)$.

Find and interpret the sum to describe the diver's present depth.

Answer 1

Compute diver's present depth:

Given the diver dives from the surface to $81$ $\mathrm{ft}$ below the surface.

So, it means he is going downwards and for downward direction we use negative sign so it becomes $-81$.

Similarly when the dives $13$ more $\mathrm{ft}$ it means he again going downwards so again we use negative sign then it becomes $-31$.

Then the sum of the depth will be $-81+\left(-31\right)$

So, Sum is$-94$.

Since, the sum is $-94$, the diver's present depth will be $94\mathrm{ft}$ below the surface.

Hence, diver's present depth is $94\mathrm{ft}$ below the surface.