Originally Posted by
MarkFL Yes, that will lead you to the correct result if you solve for 2x, however we are being asked for Harry's age, and so I would set it up as follows:
Let:
$\displaystyle H$ = Harry's age, and then:
$\displaystyle 2H$ = Jack's age and
$\displaystyle \frac{H}{2}$ = Hannah's age.
Then, use the information regarding the sum of the ages:
$\displaystyle 2H+H+\frac{H}{2}=63$
Solving this equation will directly give us the quantity we are asked to compute.
Neither approach is necessarily superior to the other though. I simply tend to express things in terms of the quantity we seek, so that we explicitly solve for that variable to answer the question.