Question

Taking sea level as zero, distance below sea surface as negative and distance above sea surface as positive, find the integers corresponding to the following situation:
A shark, swimming 40 m deep, sees a diver 20 m above him. The shark immediately rises 30 m to attack the diver, who dives deeper by 10 m. A rescue helicopter comes to the diver's aid and hovers 20 m above the surface. The helicopter drops a shark repellent which causes the shark to dive 30 m.
Position of the shark after diving is

• A. - 40 m
• B. - 30 m
• C. - 20 m
• D. 20 m

Answer 1

The correct option is A - 40 m

Before the drop of the shark repellent by the rescue helicopter, the position of shark = - 10 m
After the drop of the shark repellent, the shark dives deeper by 30 m.
$\Rightarrow$ 30 m deeper signifies - 30 m
$\therefore$ The finial position of the shark = $(-10)+(-30)$ = $-40$ m