In a group of 55 people, 33 are coffee drinkers and 12 are tea drinkers.

Question

Assuming that no one in this group drinks both tea and coffee, what is the probability that a person picked at random from the group does not drink tea or coffee?

A. 

B. 

C. 

D. 

Answer 1

D. 2/11

12+33 = 45 who drink

55-45 = 10 who don't drink

55 total

Pr(not drinking) = 10/155

10/55 = 2/11

Answer 2

(55 - 33 - 12) / 55 = ?