Probability Solved Questions For IBPS, SBI and Other Bank Exams - Page 4

You will find 14 problems in 4 pages..

Probability Problems Solved Questions (Page 4 of 4)

Question 1

In a school, 45% of the students play football, 30% play volleyball and 15% both. If a student is selected at random, then the probability that he plays football or volleyball is:

a) 2/7 b) 3/5 c) 1/4 d) 4/5

Answer : b) 3/5

Solution :

Given that, 45% play football; that is, P(F) = 45/100 = 9/20
30% play volley ball; that is, P(V) = 30/100 = 6/20

And, 15% play both volleyball and football; that is, P(F And V) = 15/100 = 3/20

Now, we have to find the probability that 1 student plays football or volley ball; that we have to find, P(F or V)

We know that, P(F Or V) = P(F) + P(V) - P(F And V)
= 9/20 + 6/20 - 3/20 = 12/20 = 3/5.

Hence, the required probability 3/5.


Question 2
Two groups, A and B wrote an exam. The probability of A's pass is 2/7 and the probability of B's pass is 2/5. What is the probability that only one of them is passed out?

a) 5/6 b) 1/3 c) 12/43 d) 18/35

Answer : d) 18/35

Solution :

Let A be the event of the group A pass
Let B be the event of the group B pass

Then, A'= Event of the group A's fail and B'= event of the group B's fail.

Therefore, p(A) = 2/7 and p(B) = 2/5,
P(A') = 1 - P(A) = 1- 2/7 = 5/7 and P(B') = 1- P(B) = 1- 1/5 = 4/5

Required probability = P[( A And B') Or (B And A')]
= P[( A And B') Or (B And A')]
= P[( A And B') + (B And A')]
= P[( A And B')] + p[(B And A')]
= p(A) x p(B') + P(A') x P(B)
= (2/7 x 4/5) + (2/5 x 5/7)
= (8/35 + 10/35) = 18/35


Question 3
A boy gets a chance of 55% to win 1st round of a game and a girl gets a chance of 60% to win 2nd round of the game. In what % of cases are they likely to contradict each other, narrating the same incident?

a) 49% b) 54% c) 71% d) 38%

Answer : a) 49%

Solution :

Let A be the event that a boy wins 1st round
Let B be the event that a girl wins 2nd round.

Then, A' = Event that the boy losses 1st round and B' = event that the girl losses 2nd round.
Therefore, P(A) = 55/100 = 11/20, P(B) = 60/100 = 12/20.
P(A') = 1- (11/20) = 9/20 and P(B') = 1- (12/20) = 8/20

First, we have to find the probability that they contradict each other;
That is, P( A And B contradicts each other)
= P[(boy win in 1st round And girl losses in 2nd round) (Or) (boy losses in 1st round And girl wins in 2nd round)
= P[(A And B') Or (A' And B)] = P[(A And B')] + p[(A' And B)]
= P(A) x P(B') + P(A') x P(B)
= 11/20 x 8/20 + 9/20 x 12/20
= 88/400 + 108/400
= 196/400

We have to find the %.
Required % = (196/400)x100 = 49%.


Probability Problems Solved Questions (Page 4 of 4)

Score Well In SBI & IBPS, PO & Clerk Exams

Related pages


pragati grameen bankproblems on mensurationopenings in syntelirda questionsinternational airport in kerala listtypes of crossing of chequeinternational airports listtmb indiabooks for ibps exam preparationsbi bank po exam booksbanking gktmb i bankingsyllogism examples for bank pomarked price and discount formulanabard establishedsbi.cmhow to solve permutation and combination problemssyllogisms questionsaptitude on probabilityproblems on hcfgeneral awareness for bank exams with answersratio and proportion problem solving with solutionsyllogism questionhow to solve reasoning puzzlessbi clerk exam question papersrbi test papersipbs bankextreme happiness synonymsratio and proportion tutorialsyllogisms questionsibps officialnames of all chief ministers of indian stateslist of airport in tamilnaducomputer questions for ibpsquantitative aptitude tutorialsmaths profit and losspallavan gramabank exam tutorialseasy venn diagramhow to solve surdssolved examples of compound interestcomputer gk questions with answerscareer sbi bankpuzzels in hindiibps salarysbi bank questionspremutation and combinationmahila diwasrtgs upper limitinternational airports list in indiacurrent affairs & gktricks to solve maths questions in bank examantonyms of profusenames of all chief ministers of indian statesantonyms for damagecurrent affairs gk questionspallavan bankallegations and mixtures problemsallegation and mixturecomputer awareness for bankingname of chennai sea portindia's largest fresh water lakequestions on mensurationhow to solve mensuration problempermutation combination problemsibps po quantitative aptitude questions with answersmultiplication table upto 20solved examples of permutation and combinationbank exams booksdifference between open and crossed chequesyllogism problemssyllogism possibility questions