if there are 39 people in a room and everyone has to shake hands with everyone exactly once, how many handshakes are there?

Which category do all of these shapes belong to

323.6 divided by 47 rounded to the nearest tenth

The thickest vinyl floor tiles available are 1 over 8 inch thick. The thinnest tiles are 1 over 20 inch think. How many thin tiles would equal the thickness of one of the thick tiles?

What is the height of the prism if the base is 6 inches and the volume is 42 inches

8 - 2x = 2 (3 - x) + 2

Solve the equation if x = 7. 5x + 9

How do I simplify the radical: square root of 324

Checks that have been processed by the bank are no longer negotiable are

Why is 21 over 30 bigger than 2 over 3?

9 weeks 5 days - 1 week 6days =