# Thread: Another binomial probability question

1. ## Another binomial probability question

1. At a fun fair booth, a signboard, as shown in Table 3, stated the criteria of winning a daily prize and a grand prize.
Table 3
Type of prizes
Criteria to win the prize
Daily prize
Win at least 3 out of 5 games in a day
Grand prize
Win a daily prize in at least 4 out of 5 days
The probability of winning a game is 0.3. Assuming that the chance of winning in one game is independent of another, what is the probability of a playerwinning
• the daily prize?
• the grand prize?

2. Originally Posted by dorwei92
1. At a fun fair booth, a signboard, as shown in Table 3, stated the criteria of winning a daily prize and a grand prize.

Table 3

Type of prizes
Criteria to win the prize
Daily prize
Win at least 3 out of 5 games in a day
Grand prize
Win a daily prize in at least 4 out of 5 days

The probability of winning a game is 0.3. Assuming that the chance of winning in one game is independent of another, what is the probability of a playerwinning
• the daily prize?
• the grand prize?
This question is done using the binomial distribution. What do you think the random variable is? What is n in each case? What is p in each case?

3. my working is 5C3 (0.3)^3 (0.7)^2
but my answer could not tally with the one on the answer sheet
i suppose there should be anything mistake in this statement, but why is it that i could not get the same answer?

4. Originally Posted by dorwei92
my working is 5C3 (0.3)^3 (0.7)^2
but my answer could not tally with the one on the answer sheet
i suppose there should be anything mistake in this statement, but why is it that i could not get the same answer?
At least 3 means you have to calculate Pr(X = 3) + Pr(X = 4) + Pr(X = 5).