# Thread: Hi I need help with this question...

1. ## Hi I need help with this question...

1a) One particular high school encourages students to donate blood. The high school gym is set up for this purpose. This distribution of blood types in NA is as follows:
Type O: 44%
Type A: 42%
Type B: 10%
Type AB: 4%
What is the probability that the first two people in line up have the same blood type?
I m not sure how to do this question?
1b) what is the probability that none of the first five people in line up have the type AB blood?
I m not sure how to do this question?

2. Originally Posted by melissa4ever
1a) One particular high school encourages students to donate blood. The high school gym is set up for this purpose. This distribution of blood types in NA is as follows:
Type O: 44%
Type A: 42%
Type B: 10%
Type AB: 4%
What is the probability that the first two people in line up have the same blood type?
I m not sure how to do this question?
This is the probability that they are both "O", plus that they are both "A",
plus that they are both "B", plus that they are both "AB".

so:

$\displaystyle p=0.44^2 + 0.42^2 + 0.10^2 + 0.04^2$

1b) what is the probability that none of the first five people in line up have the type AB blood?
I m not sure how to do this question?

probability that astudent is not "AB" is 1 minus the probability that they are "AB", then the prob that none of them are "AB" is:

$\displaystyle p=(1-0.04)^5$

RonL