# 7000+ Probability Aptitude Questions with Solutions Pdf - 1

Question: 1

The letters of word 'SOCIETY' are placed in a row. What is the probability that three come together?

(A) $${1}/{7}$$

(B) $${2}/{7}$$

(C) $${3}/{7}$$

(D) $${4}/{7}$$

Ans: A

There are 7 letters in the word ‘SOCIETY’ which can be arranged in 71 ways. Considering the three vowels in the word ‘SOCIETY’ as one letter, we can arrange 5 letters in a row in 5! ways. Also, three vowels can themselves be arranged in 3! ways.

∴ The total number of arrangements in which three vowels come together are 5! × 3!

Hence, the required probability = $${5! × 3!} /{7!}$$ = $${3 × 2 × 1}/ {7 × 6}$$ = $${1}/{7}$$.

Question: 2

In a simultaneous toss of 2 coins, then find the probability of no tail

(A) $${1}/{2}$$

(B) $${1}/{4}$$

(C) $${2}/{3}$$

(D) $${3}/{4}$$

Ans: B

Sample space S = {HH, HT, TH, TT}

Number of exhaustive cases = 4.

There is only one favourable case HH.

∴ P (no tails) = $${1}/{4}$$.

Question: 3

In a single throw of 2 dice, the probability of getting a total of 7.

(A) $${1}/{6}$$

(B) $${1}/{18}$$

(C) $${5}/{6}$$

(D) $${5}/{36}$$

Ans: A

A total of 7 may be obtained in 6 ways, viz,

(1, 6) (2, 5), (3, 4), (5, 2), (6, 1).

∴ Required probability = $${6}/ {36}$$ = $${1}/{6}$$.

Question: 4

The probabilities that a student will receive an A, B, C or D grade are 0.30, 0.38, 0.22 and 0.01 respectively. What is the probability that the student will receive at least B grade?

(A) 0.38

(B) 0.42

(C) 0.68

(D) None of these

Ans: C

P(at least B grade) = P(B grade) + P(Agrade)

= 0.38 + 0.30 = 0.68.

Question: 5

In a single throw of 3 dice, find the probability of getting a total of 17 or 18.

(A) $${1}/{18}$$

(B) $${1}/{4}$$

(C) $${1}/{36}$$

(D) $${1}/{54}$$

Ans: D

Number of exhaustive cases in a single throw of three dice

= 6 × 6 × 6 = 216

Cases favourable to a total of 17 are (5, 6, 6), (6, 5, 6), (6, 6, 5)

Number of cases favourbale to a total of 17 or 18 is 4.

∴ P( a total of 17 or 18) = $${4}/{216}$$ = $${1}/{54}$$

- 100+ Probability Aptitude Questions and Answers
- 100+ Probability Questions for Bank PO, SO, Clerk Exams
- Top 1,000+ Probability Questions and Answers Pdf
- 100+ Probability Questions and Answers for SSC Exams
- 1000+ Tsehay Bank Exam Questions and Answers Pdf
- NIB International Bank Exam Questions and Answers Pdf
- 7000+ Probability Questions for IBPS, SBI PO, SO, Clerk Bank Exams
- 7000+ Hibret Bank Aptitude Questions and Answers Pdf
- 7000+ Probability Questions for IBPS Clerk Pdf
- 7000+ Probability Aptitude Questions with Solutions Pdf

Samacheer Kalvi Class 7 Science Measurement Questions More

Atomic Structure MCQ Quiz Questions for Class 7 More

Samacheer Kalvi Class 7th Term 1 Atomic Structure Questions More

Samacheer Kalvi Class 11 Computer Ethics Questions More

Samacheer Kalvi Class 11 Computer Science Number System Questions More

1000+ Advanced Operating System MCQ with Answers Pdf More

Fill in the blanks with Suitable Articles for TNPSC Group 1, 2, 2a, 4, VAO More

Computer Gk Objective Questions and Answers More

100+ Direct and Indirect Democracy UPSC Quiz Questions More

1000+ Chemical Engineering interview Questions and Answers Pdf More