Mary is 24. She is twice as old as Ann was when Mary was as old as Ann is now. How old is Ann?
I'll admit, rosala....this one IS a "stumper." I think the verbiage in the problem is the confusing thing....until Alan and Melody explained it...I didn't see it, either.
Using what they said......
Mary's age now = 24
So...some years ago (let's call this "x") Mary was as old as Ann is now. And let's call Ann's current age "A" Therefore:
24 - x = A .......Let's call this "Equation 1"
And, as Alan has noted, x years ago, Ann's age was just, A - x.
Now here's the tricky part............"Mary.... is twice as old as Ann was"......
Let's stop right there........"is twice as old as Ann was" means that Ann's age at the time, (A - x), times 2 must equal Mary's age now - (24) !!!
OR, equation-wise......
(A - x) * 2 = 24 ........divide by 2 on both sides......
(A - x ) = 12 .........add x to both sides.......
A = 12 + x Let's call this "Equation 2"
And remember, from Equation 1, we have that 24 - x = A
Therefore Equation 1 must equal Equation 2 because A = A....so we have.....
24 - x = 12 + x ......add x to both sides......
24 = 12 + 2x ......subtract 12 from both sides.......
12 = 2x ......divide both sides by 2.....
x = 6
Therefore, since A = 12 +x, then 12 + 6 = 18 and that's Ann's current age!!!
P.S.....The complex wording of this problem makes it almost indecipherable. I might have stated it thusly:
Mary is 24. Ann is younger. When Mary was Ann's current age, Ann was half of Mary's current age. How old is Ann??
Yeah...I think that works...!!!
