Answer:
Onyango is 48, his daughter is 16 and his son is 12
Explanation:
Let's call Onyango's age x, therefore his daughter and son's ages are 1/3 x and 1/4 x respectively. We can write:
x + 8 = 12 + (1/3x + 8 + 1/4x + 8)
x + 8 = 7/12x + 28
5/12x = 20
x = 48 → 1/3x = 48 / 3 = 16, 1/4x = 48 / 4 = 12