The surface area to volume ratio of a cube is 2 to 5. Find the length of each side.

2 answers

let each side be x

6x^2 / x^3 = 2/5
2x^3 = 30x^2
2x^3 - 30x^2 = 0
2x^2(x - 15) = 0
x = 0, no cube
or
x = 15

check:
volume = 15^3 = 3375
SA = 6x^2 = 1350
1350/3375 = 2/5 , YEAHH
thank you