### CFA Practice Question

There are 985 practice questions for this topic.

### CFA Practice Question

Students at University X must be in one of the class ranks: freshman, sophomore, junior, or senior. At University X, 35% of the students are freshman and 30% are sophomores. If a student is selected at random, the probability that he or she is either a junior or a senior is ______.

A. 35%
B. 65%
C. 30%
Correct Answer: A

Using the addition rule, because freshman and sophomore are disjoint, P(freshmen or sophomore) = P(freshman) + P(sophomore) = 0.35 + 0.3 = 0.65.
The probability of the event junior or senior is 1 minus the probability that this event does not occur, namely 1 minus the probability of the event freshman or sophomore. Its probability is thus 1 - 0.65 = 0.35.

### User Contributed Comments3

User Comment
nichmax Tricky Qs
bidisha when its "mutually exclusive", if one happens then other cannot happen then don't subtract P(A.B)
sgossett86 i got one right
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