Question

The following table shows the blood groups of 30 students of a class.
Blood group
А
B
O
AB
Number of students
9
7
11
3
One student of the class is chosen at random. What is the probability that the chosen student
has the blood group a. A and b. AB?
​

Answer 1

Answer:

I m assuming

blood grp NO . STUDENTS

A. 9

B. 7

O. 11

AB 3

Step-by-step explanation:

1) 3/10

steps

total no. of students = 30

n(S)=30

let A be the event that the blood group of students in a class is A

n(A) = 9.

p(A)=n(A)/n(S)

= 9/30

= 3/10

2) 1/10

total no. of students = 30

n(S)=30

let B be the event that the blood grp of students in a class is AB.

n(B) = 3

p(B)=n(B)/n(S)

= 3/30

= 1/10

note : the formula is very much imp . it carries 1/2 - 1 mark.

writing the formula is a must.

I hope I helped u out.