How do u do this without a calculator

(2.3x10^12)divided(4.6x10^3)

I can only give possible combination of the ages. Had the sum of the ages been given, then the 3 specific numbers would have been derived.

We need to do prime factorization of 72.

72 ÷ 2 = 36
36 ÷ 2= 18
18 ÷ 2 =  9
  9 ÷ 3 =  3
  3 ÷ 1 = 1

1 x 2 x 2 x 2 x 3 x 3 = 72

Possible combinations:

1 x 8 x 9 = 72           1 + 8 + 9 = 18
1 x 4 x 18 = 72         1 + 4 + 18 = 23
2 x 4 x 9 = 72            2 + 4 + 9 = 15
3 x 4 x 6 = 72            3 + 4 + 6 = 13