Question

People surveyed a group of 1000 people and found that only 2% have type AB blood.
What is the probability that there is a type AB donor among the first five people checked? (Answer 0.096).
What is the probability that the first type AB donor will be found among the first 6 people (Answer 0.114)
What is the probability that there won't be a type AB donor before the 10th person checked? (Answer 0.834)

How do you solve these questions?

Answer 1

The probability of there being one in the first 5 people is:
1 - P(all are not AB)
1- (0.98^5) // 98% chance of each of 5 in a row not being AB

Answer 2

For part d, how would I solve that? (Prob won't be type AB before 10th person?

Answer 3

Same for the second one, with one more person:
The probability of there being one in the first 5 people is:
1 - P(all are not AB)
1- (0.98^6) // 98% chance of each of 6 in a row not being AB

Answer 4

That means there will be no AB in the first 9. Which is a 98% chance, 9 times in a row:
0.98^9

Answer 5

You truly are a life saver. Thanks a ton!

Answer 6

glad to help