Physics 104 Homework #5 Due Tues. Oct. 17, 2000

Each of the problems below is meant to be similar to the problems you have already seen worked out, either
in earlier homeworks or in lecture.  Reveiw those problems to find the similarities if you are stuck.

1) [15 pts]  A student is taking a multiple choice exam.  Each question has 4 possible answers.
Assume that the student has not studied, and is guessing blindly.  If the exam has 10 questions,

a) What is the probability that the student gets all answers correct?
b) What is the probability that the student gets all answers wrong?
c) What is the probability that the student gets more than one answer wrong?

2) [15 pts]  A jar contains 2 red balls, 2 blue balls, and 2 green balls.  A blindfolded person comes and randomly
draws three balls from the jar.  The order in which the balls are drawn does not matter.

a) What is the probability that the three balls are all of different color?
b) What is the probability that two of the balls are blue and the third is red?
c) What is the probability that two balls are the same color and the third is not?

3) [20 pts]  You are dealt 5 cards from an ordinary, randomly shuffled, 52 card deck.

a) What is the probability that the first card is a Jack, and the 5th card is a six, and the other cards are
neither Jacks nor sixes?
b) What is the probability that in the five cards there will be exactly one Jack and one six?
c) What is the probability that in the five cards there will be exactly two Jacks and one six?
d) What is the probability that in the five cars there will be no Jacks or sixes?