70 of the students who are taking MAT 094 have entered by pl

70% of the students who are taking MAT 094 have entered by placement. 30% have taken MAT 092. If three people are selected at random, what is the probability that all three have entered by the placement test? 62% of people say that vanilla is their favorite flavor of ice cream. Choose a group of 4 adults at random. The probability that none of them say their favorite flavor of ice cream is vanilla is: It has been reported that 5% of all cars on the highway are traveling at speeds in excess of 70 mph. If the speeds of four random automobiles are measured via radar, what is the probability that at least one car is going over 70 mph?

Solution

22.

P(all placement) = P(placement)^3 = 0.70^3 = 0.343 [answer]

23.

P(none) = P(not vanilla)^4 = (1-0.62)^4 = 0.02085136 [answer]

24.

P(at least one) = 1 - P(none)

= 1 - (1-0.05)^2

= 0.0975 [ANSWER]