Answer
a) $7200$ $ft-lb$
b) $7200$ $ft-lb$
Work Step by Step
a)
The work done by the gorilla in lifting its weight of 360 pounds to a height of 20 feet is
$W$ = $Fd$ = $(360 lb)( 20 ft)$ = $7200$ $ft-lb$
b)
The amount of time it takes the gorilla to climb the tree does not change the amount of work done, so that work done is still $7200$ $ft-lb$.