Jasper sold one set of barbells for 99 euros (he’s Dutch, remember), and he made a 10% profit on the deal. He sold a second set for 99 euros, but this time he took a 10% loss. Counting the two sales together, did he gain, lose, or come out even?
Let x be the cost of the first set of weights.
Let y be the cost of the second set.
Let y be the cost of the second set.
| Cost | + | profit | = | selling price |
| x | + | 0.10x | = | 1.10x = €99 → x = €90. |
| y | – | 0.10y | = | 0.90y = €99 → y = €110. |
| The costs: | The selling prices: |
|
| €90 | €99 | |
| 110 | 99 | |
| €200 | €198 |
So Jasper had an overall loss of €2.