Respuesta :

cristlynlewis
when he was 14 his dad was 42
now the child is twice 14... = 28...
CloudyJay

Let f be the father's age and his child's age be c.

As the father is 42  14 = 28 years older than the child, f = c + 28.

At the moment f = 2c, hence 2c = c + 28, and so c = 28. That is, the father's child is now 28 years old.