If Melvin sells a television at a markup price of 10% above its usual selling price, he will make a profit of $500. If he sells it at a discount of 20% of its usual selling price, he will incur a loss of $100. Find the selling price of the television
1.1 s - c = 500
0.8 s - c = -100
--------------------- subtract
0.3 s = 600