Question

Dan had $\$10$. He bought $x$ pencils, each costing $y\mathrm{cents}$. How much money did Dan have left?

Answer 1

Step 1: Convert dollar into cents.

We know that, there are $100\mathrm{cents}$ in $\$1$.

Then $\$10$ is $10·100=1000\mathrm{cents}$.

Step 2: Find the expression.

Given cost of each pencil is $y\mathrm{cents}$.

Number of pencils Dan bought is $x$.

Then, cost of $x$ pencils is $\left(xy\right)\mathrm{cents}$.

So, Dan had $1000\mathrm{cents}$ and he spend $\left(xy\right)\mathrm{cents}$.

Money left with Dan is given by $\left(1000-xy\right)\mathrm{cents}$.

Hence, Dan is left with $\left(1000-xy\right)\mathbf{}\mathit{c}\mathit{e}\mathit{n}\mathit{t}\mathit{s}$.