Please help me with this

Find the number of positive three-digit even integers whose digits are among 9, 8, 7,5, 3, and 1.

This is so hard and it’s for a test

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.