7a) How many different sums of money can be made from a 2$ bill, a 5$ bill and a 10$ bill

b) How many different sums of money can be made from the bills in a as well as one more 10$ bill

c) Why does the situation become much more complicated if another 5$ bill is added

11. The prime factorization of 540 is 2 X 2 X 3. Find the number of divisors of 12 other than 1 by finding all combination of these numbers

The prime factorization of 540 is 2 X 2 X 3 X 3 X 3 X 5. Find the other numbers of divisor of 540. Other then 1