Mary’s father is four times as old as Mary. Five years ago he was seven times as old. How old is mary?	Choose the correct answer
A) 6
B) 8
C) 10
D) 12
E) 15
The problem involves age.   The question asks, “How old is each now?”, which means it’s asking for the ages of both   Mary and her father.   Let x Mary’s current age   4x Mary’s father’s current age   x-5 Mary’s age 5 years ago   4x-5 Mary’s father’s age 5 years ago   The problem states that 5 years ago, Mary’s father’s age 4x-5 was equal to seven   times Mary’s age7(x-5)   Write the equation.   4x-5=7(x-5)   4x-5=7x-35   30=3x   x=10   4x=40   Mary’s current age is 10 years old   correct answer 10
<result>C</result>
Mary’s father is four times as old as Mary. Five years ago he was seven times as old. How old is mary?