Consider the problem: After charging for 1/3 of an hour, a phone is at 2/5 of its full power. How long will it take the phone to charge completely? Decide whether each equation can represent the situation.

Pyotr tchaikovsky sporting goods operates on a 45% overhead based on the selling price, which results in an overhead of $65.34 on the newest version of an air hockey game set. if the air hockey game set costs pyotr tchaikovsky sports $49.32, find the selling price, the markup, and the net profit.