Question

The present age of the father is twice the age of his daughter. Ten years ago, the

Answer 1

Answer:

          The father is 40 and the daughter is 20.

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