Question

In an intro stats class, 57% percent of students eat breakfast in the morning and 80% of students floss their teeth. Forty-six percent of students eat breakfast and also floss their teeth.

3. What is the probability that a student from this class eats break feast but does not floss their teeth?
A. 57%
B. 11%
C. 34%
D. 9%
E. 91%

Answer 1

Answer: B. 11%

Explanation:

Let A = Event that students eat breakfast in the morning.

B= Event that students floss their teeth.

We are given P(A)=57%=0.57

P(B)=80%=0.80

P(A∩B) = 46% =0.46

Now, the probability that a student from this class eats break feast but does not floss their teeth :-

`P(A-B)=P(A)-P(A\cap B)\\\\ = 0.57-0.46=0.11=11\%`

Hence, the probability that a student from this class eats break feast but does not floss their teeth= 11%