Both cylinder are similar
Volume of a cylinder is πr^2h
if we consider both has same radius as they are similar
Lets say V1 is volume of small cylinder and V2 is volume of big cylinder.
V1/V2=πr^2x5/πr^2xh
125/343=5/h
0.36=5/h
h=5/0.36
h=13.72 ft
The answer is 15
these chords are congruent because the radius of the circle are perpendicular to the them
so we can find EF by making an equation:
so EF is = 3(15)+5=50
good luck