SOLUTION: Noah is 40, Mary is 13. How many years ago was Noah four times as old as Mary?

Question 770384: Noah is 40, Mary is 13. How many years ago was Noah four times as old as Mary?
Answer by Edwin McCravy(20055) (Show Source): You can put this solution on YOUR website!
Noah is 40, Mary is 13. How many years ago was Noah four times as old as Mary?

Let the answer be "x years ago".

Noah's age x years ago = 40-x

Mary's age x years ago = 13-x

The equation comes from:


              

                40-x = 4(13-x)
                40-x = 52-4x
                  3x = 12
                   x = 4

Answers: 4 years ago Noah was 36.  4 years age Mary was 9.

That checks because 36 is 4 times 9.

Edwin

RELATED QUESTIONS
nick is twice as old as Noah. Nine years ago, nick was five times as old as Noah. How old (answered by mananth)

Mary is twice as old as Rachel will be in seven years. Four years ago, Mary was four... (answered by ankor@dixie-net.com)

Noah is 56 years old. Kayla is 36 years old. How many years ago was Noah's age 2 times... (answered by ikleyn)

Sarah's father is four times as old as mary. Five years ago he was seven times as old.... (answered by stanbon)

Mary�s father is four times as old as Mary. Five years ago, he was seven times as old.... (answered by josmiceli)

Jack is 24 years older than Mary is now. Four years ago, he was seven times as old as... (answered by josmiceli)

John is 3 years older than Mary. Five years ago he was four times as old as Mary was... (answered by josgarithmetic,MathTherapy)

Mary's mother is 3 times as old as Mary, 4 years ago Mary was 1/4 her mothers age. How... (answered by ewatrrr)

mary is 5 times as old as her daughter, and. three years ago she was 9 times as old as... (answered by jorel1380)