Answer:
<h3>
The father is 40 and the daughter is 20.</h3>
Step-by-step explanation:
x - the present age of the daughter
2x - the present age of the fathter
x - 10 - the age of the daughter ten year ago
2x - 10 - the age of the fathter ten year ago
Father is older than his dauther, so:
2x - 10 = (x - 10) + 20
2x - 10 = x - 10 + 20
2x - 10 = x + 10 {subtract x from both sides}
x - 10 = 10 {add 10 to both sides}
x = 20
2x = 2·20 = 40
