Probability-Quiz-7

Probability Quiz-7

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. Four numbers are multiplied together. Then, the probability that the product will be divisible by 5 or 10 is:

•  369/625
•  399/625
•  123/625
•  133/625

Solution

Q2.One Indian and four American men and their wifes are to be seated randomly around a circular table. Then the conditional probability that the Indian man is seated adjacent to his wife given that each American man is seated adjacent to his wife, is:

•  1/2
•  1/3
•  2/5
•  1/5

Solution

Q3.  If p is the probability that a man aged x will die in a year, then the probability that out of n men A₁,A₂,…A_n each aged x,A₁ will die in an year and be the first to die is:

•  1-(1-p)ⁿ
•  (1-p)ⁿ
•  1/n[1-(1-p)ⁿ]
•  1/n(1-p)ⁿ

Solution

Q4. A hat contains a number of cards with 30% white on both sides, 50% black on one side and white on the other side, 20% black on both sides. The cards are mixed up, and a single card is drawn at random and placed on the table. Its upper side shows up black. The probability that its other side is also black is:

•  2/9
•  4/9
•  2/3
•  2/7

Solution

Q5. A pair of four dice is thrown independently three times. The probability of getting a score of exactly 9 twice is:

•  8/9
•  8/729
•  8/243
•  1/729

Solution

Q6. The numbers 1,2,3,…n are arrange in random order. The probability that the digits 1,2,3,…,k(k<n) appears as neighbours in that order is:

•  1/n!
•  k!/n!
• (n-k)!n!
•  (n-k+1)!n!

Solution

Q7. A and B toss a fair coin each simultaneously 50 times. The probability that both of them will not get tail at the same toss is:

•  (3/4)⁵⁰
•  (2/7)⁵⁰
•  (1/8)⁵⁰
•  (7/8)⁵⁰

Solution

Q8. A fair coin is tossed 5 times, then the probability that no two consecutive heads occur is:

•  11/32
•  15/32
•  13/32
•  None of these

Solution

Q9. Three ships A,B and C sail from England to India. If the ratio of their arriving safely are 2:5, 3:7 and 6:11, respectively, then the probability of all the ships for arriving safely is:

•  18/595
•  6/17
•  3/10
•  2/7

Solution

Q10. A drawer contains 5 brown socks and 4 blue socks well mixed. A man reaches the drawer and pulls out socks at random. What is the probability that they match?:

•  4/9
•  5/8
•  5/9
• 7/12

Solution