SOLUTION: 8. Ricardo is 4 years less than twice as old as his sister. The sum of their ages is 20. How old is Ricardo? A) 8 B) 10 C) 12 D) 14

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Question 106637: 8. Ricardo is 4 years less than twice as old as his sister. The sum of their ages is 20. How old is Ricardo?
A) 8
B) 10
C) 12
D) 14

Answer by HyperBrain(694) About Me  (Show Source):
You can put this solution on YOUR website!
Let x= the age of the sister
____y=age of Ricardo

THen,
2x=twice the age of his sister
x+y=sum of their ages
IF Ricardo is 4 years less than twice as old as his sister,
y=2x-4
If the sum of their ages is 20,
x%2By=20
But,
y=2x-4
Thus,
x%2B2x-4=20
3x-4=20
3x-4%2B4=20%2B4
3x%2B0=24
3x=24
3x%2F3=24%2F3
x=8
Solving for y,
y=2x-4
y=2%288%29-4
y=16-4
y=12
Therefore, Ricardo is 12 yrs. old!

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