Permutations with restrictions

Twenty students are available for 7 scholarships. How many ways can the scholarships be warded if;
a) a student can only be granted one scholarship?
b) a student can be granted more than one?

a. 20 choices for 1st scholarsjip, 19 for 2nd ... = 20P7 = 20!/13! = 390 700 800 <-------

b. 20 choices for each scholarship = 20^7 = 1 280 000 000 <-------