Question

Suppose that 50% of first year college students take a mathematics course, 40% take a biology course, and 20% take both mathematics and biology during the first year. What percent of first year college students take either mathematics or biology or both?

Answer 1

Answer:

70%

Step-by-step explanation:

Universal set = set of all first year students

P(U) = 1

P(M) = 0.5

P(B) = 0.4

P(M n B) = 0.2

The percent of first year college students take either mathematics or biology or both

P(M U B) = ?

P(M u B) = P(M n B') + P(M' n B) + P(M n B)

P(M n B') = P(M) - P(M n B) = 0.5 - 0.2 = 0.3

P(M' n B) = P(B) - P(M n B) = 0.4 - 0.2 = 0.2

P(M u B) = 0.3 + 0.2 + 0.2 = 0.7 = 70%