posted by Annabella Richards on .
3 consecutive numbers multiply to 4080. What are the numbers?
Let the middle number be x.
(x-1)x(x+1) = x^3 - x = 4080
x = 16 works
I did not solve the cubic equation, but knew the answer had to be an integer slightly larger than the cube root of 4080.
The numbers are 15, 16 and 17.