Question 811995
Sorry but a cube has all sides equal.
Maybe you mean 120 cubic inch box

l=w+2,
h=l+3,
l*w*h=120
(W+2)*W*(W+2+3)=120
W (W+2) (W+5) = 120
W (W^2+7W+10) = 120
W = 3
l=5
h=8