aA integer form 1 to 5 is secretly chosen what is the probab

a)A integer form 1 to 5 is secretly chosen, what is the probability that you guess a right number?

b)Two fair dice. If you roll a 8 you lose. If it\'s not 8, then what is the probability that the following two rolls of dice give identical results?

c)If you have 3 disjoint boxes, and a 10% chance of getting a ball in each box. What is the probability that you get no ball?

d)Choose integers a and b(a and b are distinct) from 1 to 50(with replacement), what is the probability that a*b is even?

e)Suppose there a 4 indistinguishable penny, and only one of them is real. You pick three of them. What is the probability that you didn\'t pick the real one?

f)Suppose there a 4 indistinguishable penny, and only one of them is real. You pick one of them and put it away. What is the probability that the real penny is the last pick?

Solution

a) The probability that you guess a right number = 1/5 = 0.2 Answer

b) Event A: Probability that the following two rolls of dice give identical results.

    Event B: Its not 8

    P (A/B) = P(A intersection B)/ P(B)

               = (5/36) / (31/36) = 5/31   = 0.161 Answer

c)

Desired probability = 0.9/3 = 0.3 Answers

d)

Probability = (50*25) / 2500 = 0.5 Answers

e)

Probability = 1/ 4C3 = 1/4 = 0.25 Answers

f)

Probability = 1 - 0.25 = 0.75 Answer