|
Question 314941: Jackie is twice as old as John. Ten years ago, Jackie was three times as old as John was ten years ago. How old is each one new? Is there a certain format to use when doing these type of word problems? I get lost on this. Thank you for any help you provide.
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Jackie is twice as old as John.
Ten years ago, Jackie was three times as old as John was ten years ago.
How old is each one now?
:
Here is one method, that's pretty easy
:
Let x = Jackie's present age
Let y = John's present age
:
Write an equation for each statement:
:
"Jackie is twice as old as John."
x = 2y
:
Ten years ago, Jackie was three times as old as John was ten years ago.
x - 10 = 3(y - 10)
x - 10 = 3y - 30
x = 3y - 30 + 10
x = 3y - 20
:
From the 1st equation, replace x with 2y
2y = 3y - 20
+20 = 3y - 2y
y = 20 yrs is John's present age
then
x = 2(20)
x = 40 is Jackie's present age
:
:
Check solutions in the statement:
"Ten years ago, Jackie was three times as old as John was ten years ago."
40 - 10 = 3(20 - 10)
30 = 3(10), confirms our solutions
|
|
|
| |
