Question

Amelia had a total of 1,260 marbles and table tennis balls. She had 40 fewer marbles than table tennis balls.How many table tennis balls did she have?

Answer 1

Let 'x' represent number of marbles

Let 'y' represent number of table tennis balls

Amelia had a total of 1,260 marbles and table tennis balls,

The mathematical representation is,

$x+y=1260\ldots\ldots\text{.}.1$

She had 40 fewer marbles than table tennis balls.

The mathematical representation is,

$x=y-40\ldots\ldots\ldots2$

Substitute x = y - 40 from equation 2 into equation 1 to solve for y

$\begin{gathered} y-40+y=1260 \\ y+y=1260+40 \\ 2y=1300 \\ \frac{2y}{2}=\frac{1300}{2} \\ y=650\text{ table tennis balls} \end{gathered}$

Hence, she has 650 marbles.