1) If a discount of 20% off the retail price of a desksaves Mark $45, how much did he pay for the desk?

A. $145
B. $160
C. $180
D. $210
E. $215

2)

Jim can fill a pool carrying buckets of water in 30 minutes. Suecan do the same job in 45 minutes. Tony can do the same job in 1½ hours. How quickly can all three fill the pooltogether?

A. 12 minutes
B. 15 minutes
C. 21 minutes
D. 23 minutes
E. 28 minutes

I would very much appreciate the steps and yourexplanation.