Can I get some help? To clarify its Homework!

What is the volume of this square pyramid?

If 1/√5+1/√5+1=p+q√r , find the values of p, q and r

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.