Mark the correct alternative in each of the following:
Two persons A and B take turns in throwing a pair of dice. The first person to throw 9 from both dice will be awarded the prize. If A throws first, then the probability that B wins the game is
Let’s find out the probability of getting ‘9’ from throw of a pair of dice first:
9 can be obtained in the given 4 cases →
[(3,6), (4,5), (5,4), (6,3)]
Getting 9 →
Not getting 9 →
B will win when A won’t get 9 in his/her throw and B will get 9 in his/her throw, i.e. B wins after 1 round of throws, P
Now then,
P(B wins) = P(Getting 9 in 2nd throw) + P(Getting 9 in 4th throw) + P(Getting 9 in 6th throw) + . . . . . . .
→ GP (Geometric Progression)