# Probability – Aptitude MCQ Questions – 09

Question 1

Two brother X and Y appeared for an exam. Let A be the event that X is selected and B is the event that Y is selected.The probability of A is 1/7 and that of B is 2/9. Find the probability that both of them are selected.

 Â Â Â  A. 1/63 Â Â Â  B. 2/35 Â Â Â  C. 2/63 Â Â Â  D. 9/14

Question 2
A speaks truth in 75% of cases and B in 80% of cases. In what percent of cases are they likely to contradict each other in narrating the same event?

 Â Â Â  A. 35% Â Â Â  B. 5% Â Â Â  C. 45% Â Â Â  D. 22.5%

Question 3
Four cards are drawn at random from a pack of 52 playing cards. Find the probability of getting all the four cards of the same suit.

 Â Â Â  A. 13/270725 Â Â Â  B. 91/190 Â Â Â  C. 178/20825 Â Â Â  D. 44/4165

Question 4
There are four hotels in a town. If 3 men check into the hotels in a day then what is the probability that each checks into a different hotel?

 Â Â Â  A. 6/7 Â Â Â  B. 1/8 Â Â Â  C. 3/8 Â Â Â  D. 5/9

Question 5
There are 12 boys and 8 girls in a tuition centre. If three of them scored first mark, then what is the probability that one of the three is a girl and the other two are boys?

 Â Â Â  A. 14/75 Â Â Â  B. 22/55 Â Â Â  C. 44/95 Â Â Â  D. None of these

Question 6
A bag contains 21 toys numbered 1 to 21. A toy is drawn and then another toy is drawn without replacement.Find the probability that both toys will show even numbers.

 Â Â Â  A. 5/21 Â Â Â  B. 9/42 Â Â Â  C. 11/42 Â Â Â  D. 4/21

Question 7
The odds against an event are 5 : 3 and the odds in favour of another independent event are 7 : 5. Find the probability that at least one of the two events will occur.

 Â Â Â  A. 69/96 Â Â Â  B. 52/96 Â Â Â  C. 71/96 Â Â Â  D. 13/96

Question 8
Two dice are thrown simultaneously. Find the probability of getting a multiple of 2 on one dice and multiple of 3 on the other dice.

 Â Â Â  A. 5/12 Â Â Â  B. 11/36 Â Â Â  C. 5/36 Â Â Â  D. 13/36

Question 9
A bag contains 12 white and 18 black balls. Two balls are drawn in succession without replacement.What is the probability that first is white and second is black?

 Â Â Â  A. 18/145 Â Â Â  B. 18/29 Â Â Â  C. 36/135 Â Â Â  D. 36/145

Question 10
Four dice are thrown simultaneously. Find the probability that all of them show the same face.

 Â Â Â  A. 1/216 Â Â Â  B. 1/36 Â Â Â  C. 4/216 Â Â Â  D. 3/216