Question

Three numbers are in the ratio 2 ∶ 3 ∶ 4 and the sum of their cubes is 33957. Find the

numbers.​

Answer 1

Let the numbers be 2x, 3x and 4x

sum of cubes = 33957

⇒(2x)³ + (3x)³ + (4x)³ = 33957

⇒8x³ + 27x³ + 64x³ = 33957

⇒99x³ = 33957

⇒x³ = 33957/99 = 343

⇒x = ∛343 = 7

Numbers are:

2x = 2×7 = 14

3x = 3×7 = 21

4x = 4×7 = 28

Answer 2

Answer:

Let the numbers be 2x, 3x and 4x

sum of cubes = 33957

⇒(2x)^3 + (3x)^3 + (4x)^3 = 33957

⇒8x^3 + 27x^3 + 64x^3 = 33957

⇒99x^3 = 33957

⇒x^3 = 33957/99 = 343

⇒x = 3√343 = 7

Numbers are:

2x = 2*7 = 14

3x = 3*7 = 21

4x = 4*7 = 28