The sum of cubes of two numbers is 280. If the numbers are in the ratio 2:3, find the smallest number.

A. 4
B. 6
C. 3
D. 2

Let the numbers be 2x and 3x. (2x)³+(3x)³=280 8x³+27x³=280 35x³=280 x³=8 x=2 The numbers are 4 and 6.