# Probability · Mathematics · WB JEE

Start Practice## MCQ (Single Correct Answer)

WB JEE 2008

A person draws out two balls successively from a bag containing 6 red and 4 white balls. The probability that at least one of them will be red is...

WB JEE 2009

A and B are two independent events such that P(A $$\cup$$ B') = 0.8 and P(A) = 0.3. Then P(B) is

WB JEE 2009

Three numbers are chosen at random from 1 to 20. The probability that they are consecutive is

WB JEE 2010

Two dice are tossed once. The probability of getting an even number at the first die or a a total of 8 is

WB JEE 2010

The probability that at least one of A and B occurs is 0.6. If A and B occur simultaneously with probability 0.3, then P(A') + P(B') is

WB JEE 2011

4 boys and 2 girls occupy seats in a row at random. Then the probability that the two girls occupy seats side by side is

WB JEE 2011

A coin is tossed again and again. If tail appears on first three tosses, then the chance that head appears on fourth toss is

WB JEE 2023

Let A and B are two independent events. The probability that both A and B happen is $${1 \over {12}}$$ and probability that neither A and B happen is ...

WB JEE 2023

Let S be the sample space of the random experiment of throwing simultaneously two unbiased dice and $$\mathrm{E_k=\{(a,b)\in S:ab=k\}}$$. If $$\mathrm...

WB JEE 2022

A, B, C are mutually exclusive events such that $$P(A) = {{3x + 1} \over 3}$$, $$P(B) = {{1 - x} \over 4}$$ and $$P(C) = {{1 - 2x} \over 2}$$. Then th...

WB JEE 2022

A determinant is chosen at random from the set of all determinants of order 2 with elements 0 or 1 only. The probability that the determinant chosen i...

WB JEE 2021

Four persons A, B, C and D throw and unbiased die, turn by turn, in succession till one gets an even number and win the game. What is the probability ...

WB JEE 2020

Four persons A, B, C and D throw an unbiased die, turn by turn, in succession till one gets an even number and win the game. What is the probability t...

WB JEE 2020

A rifleman is firing at a distant target and has only 10% chance of hitting it. The least number of rounds he must fire to have more than 50% chance o...

WB JEE 2019

A problem in mathematics is given to 4 students whose chances of solving individually are $${{1 \over 2}}$$, $${{1 \over 3}}$$, $${{1 \over 4}}$$ and ...

WB JEE 2019

If X is a random variable such that $$\sigma$$(X) = 2.6, then $$\sigma$$(1 $$-$$ 4X) is equal to

WB JEE 2018

In order to get a head at least once with probability $$ \ge $$ 0.9, the minimum number of times a unbiased coin needs to be tossed is

WB JEE 2018

A student appears for tests I, II and III. The student is successful if he passes in tests I, II or I, III. The probabilities of the student passing i...

WB JEE 2017

The probability that a non-leap year selected at random will have 53 Sunday is

## Subjective

WB JEE 2008

If an unbiased coin is tossed n times. Find the probability that head appears an odd number of times.

## MCQ (More than One Correct Answer)

WB JEE 2020

A and B are independent events. The probability that both A and B occur is $${1 \over {20}}$$ and the probability that neither of them occurs is $${3 ...