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Jack
10-10-2013, 12:19 PM
Five years ago, Jim was half as old as John is now. If John is six years older than Jim, how old is John now ?

(A) 22

(B) 20

(C) 24

(D) 18

Thanks!

miranda
10-10-2013, 12:20 PM
Let x,y be the Jim’s and John’s age now respectively.
So, the proposition “Five years ago, Jim was half as old as John is now” can be written as
x-5=\frac{y}{2} (1)

and the proposition “John is six years older than Jim” can be written as
x=y-6 (2)

Solving the simultaneous equations (1) and (2)
2x-10=y \Rightarrow 2(y-6)-10=y \Rightarrow 2y-12-10=y \Rightarrow y=22

Therefore the correct answer is (A).

Jack
10-10-2013, 12:20 PM
Thank you !!