Question
A slice of thickness 1 cm is cut off from one side of a cube. If the volume of the remaining figure is 180 cubic centimeter, how ling is the edge of the original cube
Answers
Steve
If the original cube had side s, then the volume was s^3.
A 1-inch slab has volume s^2.
So, we know that s^3 - s^2 = 180
s^3 - s^2 - 180 = 0
Inspection reveals that s=6 is one answer. So, now we have
(s-6)(s^2 + 5s + 30)
The quadratic has no real roots, so s=6 is the only answer.
A 1-inch slab has volume s^2.
So, we know that s^3 - s^2 = 180
s^3 - s^2 - 180 = 0
Inspection reveals that s=6 is one answer. So, now we have
(s-6)(s^2 + 5s + 30)
The quadratic has no real roots, so s=6 is the only answer.