Probability-Quiz-3

Probability Quiz-3

Dear Readers,

Probability is an important topic in JEE advanced examination. In this exam, probability carries weightage of 7% of questions. With focused practice good marks can be fetched from this topic .

Q1. There are only two women among 20 persons taking part in a pleasure trip. The 20 persons are divided into two group, each group consisting of 10 persons. Then the probability that the two women will be in the same group is:

•  9/19
•  9/38
•  9/35
•  None of these

Solution

Q2.A box contains tickets numbered from 1 to 20. Three tickets are drawn from the box with replacement. The probability that the largest number on the tickets is 7 is:

•  2/19
•  7/20
•  1-(7/20)³
•  None of these

Solution

Q3.  South African cricket captain lost the loss of coin 13 times out of 14. The chance of this happening was:

•  7/2¹³
•  1/2¹³
•  13/2¹⁴
•  13/2¹¹

Solution

Q4. Five different marbles are placed in 5 different boxes randomly. Then the probability that exactly two boxes remain empty is (each box can any number of marbles):

•  2/5
•  3/5
•  12/25
•  None of these

Solution

Q5.A signal which can be green or red with probability4/5 and 1/5 respectively, is received by station A and then transmitted to stationB. The probability of each station receiving the signal correctly is 3/4.If the signal received at station B is green, then the probability that the original signal green is:

•  3/5
•  6/7
•  20/23
•  9/20

Solution

Q6. Let A,B,C be three mutually independent events. Consider the two statements S₁ and S₂ S₁: A and B∪C are independent S₂: A and B∩C are independent Then:

•  Both S₁ and S₂ are true
•  Only S₁ is true
• Only S₂ is true
•  Neither S₁ nor S₂ is true

Solution

Q7. A six-faced dice is so biased that it is twice as likely to show an even number as an odd number when thrown. It is throe twice, the probability that the sum of two numbers thrown is even is:

•  1/12
•  1/6
•  1/3
•  5/9

Solution

Q8.A man alternately tosses a coin and thrown a die beginning with the coin. The probability that he gets a head in the coin before he gets a 5 or 6 in the dice is:

•  3/4
•  1/2
•  1/3
•  None of these

Solution

Q9.A student appears for tests I, II and III. The students is successful if he passes either in tests I and II or tests I and III. The probabilities of the student passing in tests I, II and III are4, respectively, p,q are ½. If the probability that the student is successful is 1/2 , then p(1+q)=:

•  1/2
•  1
•  3/2
•  3/4

Solution

Q10. The probability that a random chosen three-digit number has exactly 3 factors is:

•  2/225
•  7/900
•  1/800
• None of these

Solution