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 y be the cost of the second set.
|x||+||0.10x||=||1.10x = €99 → x = €90.|
|y||–||0.10y||=||0.90y = €99 → y = €110.|
|The costs:|| The selling