SOLUTION: In four years, John's age will be the same as Peter's age now. In two years, Peter's age will be twice as John's age. How old is Peter now?

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Question 1196352: In four years, John's age will be the same as Peter's age now. In two years, Peter's age will be twice as John's age. How old is Peter now?
Found 2 solutions by ikleyn, josgarithmetic:
Answer by ikleyn(52781)   (Show Source): You can put this solution on YOUR website!
.
In four years, John's age will be the same as Peter's age now.
In two years, Peter's age will be twice as John's age. How old is Peter now?
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Let x be the Peter's age, in years (the quantity under the question).

First sentence says that John is 4 years younger than Peter;
so, John's age today is (x-4) years.


In two years, their ages will be (x+2) for Peter and ((x-4)+2) = (x-2) for John.


Next, from the problem we have this equation

    x+2 = 2*(x-2)       (In two years, Peter's age will be twice as John's age)


The setup is done. Now to the solution.

To solve the equation, simplify it step by step

    x + 2 = 2x - 4

    2 + 4 = 2x - x

      6   =   x


ANSWER.  Peter is 6 years old now.

Solved.



Answer by josgarithmetic(39617)   (Show Source): You can put this solution on YOUR website!


----------------by substitution, now in one variable equation





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