Question

A roulette wheel has 38 slots in which the ball can land. Two of the slots are green, 18 are red, and 18 are black. The ball is equally likely to land in any slot. The roulette wheel is going to be spun twice, and the outcomes of the two spins are independent.

4. The probability that it lands on red neither time is

a. 0.2244. b. 0.2770. c. 0.4488. d. 0.9474.

5. The probability that it lands once on red and once on black is

a. 0.2244. b. 0.2770. c. 0.4488. d. 0.9474.

Answer 1

4)

probability of landing on red slot = 18 / 38 =0.4736

probability of not landing on red slot = 1 - probability of landing on red slot = 1- 0.4736 = 0.5264

since two outcomes are independent

probability of landing on red neither time is = 0.5264*0.5264 = 0.2770

5)

p(first red and then black) = (18/38)*(18/38) = 0.2244

p(first black and then red) = (18/38)*(18/38) = 0.2244

The probability that it lands once on red and once on black is = 0.2244 +  0.2244 = 0.4488