a. There are 9 outcomes : 4-1, 4-2, 4-3, 4-4, 3-1, 3-2, 3-3, 2-1, 2-2
b. 32 times ( as there are 3 outcomes out of 9 that has a difference of 1, she should get a 50% odds)
c. 32 times ( as there are also 3 outcomes out of 9 that has a difference of 0)