SOLUTION: Mark is 11 years older than his sister. In 8 years, he will be twice as old as she will be then. How old are they now?

Question 97264: Mark is 11 years older than his sister. In 8 years, he will be twice as old as she will be then. How old are they now?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Mark is 11 years older than his sister. In 8 years, he will be twice as old as she will be then. How old are they now?
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NOW DATA:
Let sister be "x" yrs. old
Mark is "x+11" yrs old
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In 8 yrs DATA:
Sister will be "x+8" yrs old
Mark will be x+11+8 = "x+19" yrs old
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EQUATION:
Mark = 2*Sister
x+19 = 2(x+8)
x+19 = 2x+16
x = 3 (Sister's age NOW)
x+11 = 14 (Mark's age NOW)
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Cheers,
Stan H.

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