One year ago Liz was three times as old as her brother Jack. In two years she'll be only twice as old as Jack. How old are Liz and Jack now?

Question

This is an age related math problem with two people looking at their current ages based on the past and future.

Answer 1

L=liz's age now

J=Jack's age now

L-1 and J-1 are their ages one year ago

L-1=3(J-1)

L-1=3J-3

L=3J-3+1

L=3J-2 (to be used later)

 

L+2 and J+2 are their ages in two years

L+2=2(J+2)

replace L by 3J-2

3J-2+2=2(J+2)

3J=2J+4

3J-2J=4

J=4 is Jack's age now

L-1=3(J-1)

L-1=3(4-1)

L-1=3*3

L-1=9

L=9+1

L=10 is Liz's age now

check: last year their ages were 9 and 3; two years from now their ages will be 12 and 6