Question

A boy spent one-half of his money for a book and one-third of his money for a pen. The remaining $2.25 he saved. How much money did he have originally?

Answer 1

Let his original money is x

So, $\frac{x}{2}$ + $\frac{x}{3}$ + 2.25 = x
or, $\frac{3x+2x+(6*2.25)}{6} = x$
or, 5x + 13.5 = 6x
or, x = 13.5

So, he had $13.5 originaly. 

Thanks!

Answer 2

1 - (1/2 + 1/3) =
1 - 5/6 =
1/6 = 2.25
2.25 * 6=

13.50