Posted by Michael on .
Mary's age is 2/3 that of Peter's. Two years ago Mary's age was 1/2 of what Peter's age will be in 5 years time. How old is Peter now? Explain your workings

Mathematics 
declan,
Let Mary=Y Peter=X
Mary is 2/3 Peter's age therefore:
Y =2/3X
two years ago..mary was 1/2 peter's age in 5 years..we write the equation as:
(Y) 2 = 1/2(x+5)
substitute Y=2/3X
2/3X  2 = 1/2x + 5/2
solve for X
X=27.....therefore Y=18