is strictly increasing on [0, 5], so

and

so the integral is bounded between

Square root of 48= Square root of 16 times 3= 4 Square root of three. The square root of 48 is an irrational number!
V=LWH
if each is doubled
V=2L2W2H
V=2*2*2*LWH
V=8LWH
volume is multiplied by 8
The step in this problem is do 1/4 + 1/3= ?
and see what you get