Question 260349
First we make sure all units are the same -> 2 ft 8 in means 32 inches.
Volume of tank = LWH = 32*40 *H = 1280H
We need a proportion now:
(i) {{{10/((3/4)*(1280h)) = X/(1280h)}}}
cross multiply to get
(ii) {{{12800H = 960HX}}}
divide to get
X = 13.333 cu. ft.
--
13.3333 cu ft. (12 in / ft)^3 = 1280H cu. in.
which means
17040 cu. in. = 1280H cu. in.
H = 13.3125 in.