In Saudi Arabian currency 1 riyal equals 20 qurush. Sheik Ahab had 15 coins whose value was 205 qurush. How many coins of each kind were there?

Part a : solve - vp + 40 < 65 for v . part b : solve 7w - 3r = 15 for r show your work!

Driving 75 mph, it takes alicia 2 hours to reach the airport to go on a vacation. it then takes her 4 hours to get to her destination with the jet traveling at a speed of 400 mph. how many miles does alicia travel to get to her destination?

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.