An American roulette wheel has 38 slots numbered 00, 0, 1 through 36. 18 of the slots in the 1 through 36 are colored red, and 18 are colored black. The 0 and 00 slots are considered 'uncolored'. The wheel is spun, and a ball rounds the peripheral until gravity takes over and the ball lands in a slot. What is the probability of the ball falling into:
a. A black slot:
b. The 0 slot:
c. An odd-numbered slot:
d. The number 24: