Question

Find the cube root of each of the following numbers by prime factorisation method.

(i) 175616

(ii) 91125

Answer 1

(i) Prime factorisation of 175616 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2  x 7 x 7 x 7 

∴  3√175616 = 2 x 2 x 2 x 7 = 56

(ii) Prime factorisation of 91125 = 3 x 3 x 3 x 3 x 3 x 3 x5 x 5 x 5

∴ 3√91125 = 3 x 3 x 5 = 45