Please help me 
When buying a new car, you have a choice of 4 different models, 3 different colors, and either compact or family size. How many choices are there for one car?  
5
12
16
24


17.   
There are 20 entries in the chess tournament. How many ways can they finish in first, second, and third place? 
340
6,840
7,220
8,350