SOLUTION: john is five years older than will. twice johns age in two years is same as four times will's age one year ago. how old is john now?

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Question 1145242: john is five years older than will. twice johns age in two years is same as four times will's age one year ago. how old is john now?
Found 3 solutions by josgarithmetic, greenestamps, MathTherapy:
Answer by josgarithmetic(39616)   (Show Source): You can put this solution on YOUR website!


Note the question asked: How old is john now?
Answer by greenestamps(13198)   (Show Source): You can put this solution on YOUR website!


There is nothing wrong with the solution shown by tutor @josgarithmetic. However, they made the problem much more work than necessary!

The obvious two equations from the given information are




Given two equations in that form, the easiest solution method is substitution.

But the other tutor went to the trouble of solving the second equation for j and substituting in the first equation, leading to a lot of calculations involving fractions.

It is rather silly to do that, when the first equation already gives you one variable in terms of the other!

So substitute what's given in the first equation into the second:






So Will is 9; that makes John 9+5 = 14.
Answer by MathTherapy(10551)   (Show Source): You can put this solution on YOUR website!

john is five years older than will. twice johns age in two years is same as four times will's age one year ago. how old is john now?
Let John's age be J

Then Will's is: J - 5

Based on what's given we get: 2(J + 2) = 4(J - 5 - 1)

2J + 4 = 4(J - 6)

2J + 4 = 4J - 24

4 + 24 = 4J - 2J

28 = 2J

J, or John is:  

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