Thread: One older then the other

Jack is 6 years older than Jane. Six years ago he was twice as old as she was. How old is Jane now?

Originally Posted by Godfather

Jack is 6 years older than Jane. Six years ago he was twice as old as she was. How old is Jane now?

Let Jane's age now be x
Then Jack's age is x + 6

Six years ago, Jack's age was x and this was twice Jane's age six years ago (which is x - 6). So we have:

x = 2(x - 6)
=> x = 2x - 12
=> x = 12 --------> Jane's age now

Hello, Godfather!

Jack is six years older than Jane.
Six years ago he was twice as old as she was.
How old is Jane now?

I use a chart for most age problems.


Make a row for each person.



Make a column for "Now".



Let = Jane's age now.
Then = Jack's age now.
. . Write those in the "Now" column.




Make a column for the other time period: "6 years ago".




Six year ago, both were six years younger.
. . Jack was only years old.
. . Jane was only years old.
Write those in the second column.




It says, "Six years ago, Jack was twice Jane's age ."

. . and there is our equation: .