Question

after giving a test to a group of students, below is the summary of grades and gender.

	a	b	c	total
female	10	13	7	30
total	12	25	21	58

if a student is randomly chosen, find the probability that the student did not earn a(n) b. leave your answer as a reduced fraction.
question help: video message instructor

Explanation:

Step1: Find number of non - B students

The number of students who got A is 12 and the number of students who got C is 21. So the number of non - B students is $12 + 21=33$.

Step2: Find total number of students

The total number of students is 58.

Step3: Calculate probability

The probability $P$ that a randomly chosen student did not earn a B is the number of non - B students divided by the total number of students. So $P=\frac{33}{58}$.

Answer:

$\frac{33}{58}$