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.The probability that it lands one time on red and another time on black in any order is ________.

(A) 0.5 (B) 0.25 (C) 0.4488 (D) 0.2244

Answer 1

D is the correct option

Explanation:

The roulette can land in any possibly slot and their are 38slots

i.e the total possible event is 38

Green slot = 2

Red slot =18

Black slot =18

P(G)=2/38 =1/19

P(R)=18/38=9/19

P(B)=18/38=9/19.

The roulette will be spun twice and they are independent i.e. the occurrence of one event does not affect the occurrence of the other.

We are looking for the probability of red first and probability of black

P(R n B)=P(R)P(B), since they are independent

P(R n B)=9/19×9/19

P(R n B)= 0.2244

D is the correct option