Question

You and $4$ friends are buying tickets for a concert. The cost to buy one ticket is $c$ dollars. If you buy all the tickets together, there is a discount and the cost is $(5c-12.5)$ dollars. How much do you save per ticket when you buy the tickets together?

Answer 1

Find the amount you save per ticket when you buy the tickets together:

Given:

The cost per $1$ ticket is $c$
The cost to buy $5$ tickets $=5\times c$ dollars

If you buy all the tickets together, then there is a discount and the cost after discount is $(5c-12.5)$ dollars

The amount saved by buying all tickets can be obtained by finding the difference of cost before discount and after discount

$$\begin{gathered} =5c-(5c-12.5)dollars \\ =5c+(-5c+12.5)\{Addopposties\} \\ =12.5dollars\left\{simplify\right\} \end{gathered}$$

Hence, the amount you save per ticket when you buy the tickets together is $12.5$ dollars.