10. Mary's father is four times as old as Mary. Five years ago he was seven times as old. How old

is each now?

Mary is 10 years old, and her father is 40 years old.

Step-by-step explanation:

Let Mary's age = x.

Mary's father is four times as old, so he is 4x.

Five years ago, Mary was x - 5, and her father was 7 (x - 5).

Five years ago, Mary's father was 4x - 5.

7 (x - 5) = 4x - 5

7x - 35 = 4x - 5

3x = 30

x = 10

4x = 4 * 10 = 40

Mary is 10 years old, and her father is 40 years old.