Question

1)Twelve years ago, Mussab was five times as old as KhaledIn year's time Khaled will be half Mussab's age. How old is each man at the moment?

Answer 1

Let KhaledIn is $x$ years old, and Mussab is $y$ years old. Then we have the following equations: $y-20=5(x-20)$ and $y+1=2(x+1).$ It follows that $y=5x-80$ and $y=2x+1$. Therefore, $5x-80=2x+1$, and thus $3x=81.$ We conclude that $x=27$ and $y=2\cdot 27+1=55.$

Answer: KhaledIn is $27$ years old, and Mussab is $55$ years old at the moment.