Question 1145860: Scott is now 24 and Shannon is 12 years old. How many years ago was Scott 4 times as old as Shannon at that time?
Found 3 solutions by josgarithmetic, greenestamps, ikleyn:
Answer by josgarithmetic(39617)   (Show Source):
Answer by greenestamps(13200)  (Show Source):
You can put this solution on YOUR website!
When Scott was 4 times as old as Shannon, let their ages be 4x and x. The difference in those ages is 4x-x = 3x.
The difference in their age is given as 24-12 = 12.
We want to find when the difference of 12 years in their ages was equal to 3x:
3x = 12
x = 4
Scott was 4 times as old as Shannon when she was x=4 and he was 4x=16.
Since they are now 24 and 12, that was 8 years ago.
Answer by ikleyn(52781)  (Show Source):
You can put this solution on YOUR website! .
Do it directly, following to the condition description
Let x = "How many years ago . . . ", which is exactly the value under the question.
Then you have the equation, directly from the condition
 = 4.
Multiply both sides by (12-x). You will get
24 - x = 4*(12-x)
24 - x = 48 - 4x
4x - x = 48 - 24
3x = 24
x = 24/3 = 8.
ANSWER. 8 years ago.
CHECK. 8 years ago Scott was 24-8 = 16 years old.
8 years ago Shannon was 12-8 = 4 years old.
 = 4. ! Precisely correct !
Solved.
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