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JEE Main

IMPORTANT

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A coin is tossed until a head appears or it has been tossed thrice. Given that head doesn't appear on the first toss, the probability that coin tossed thrice is

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Important Questions on Probability

HARD

JEE Main

IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 2>Q 19

There are two urns. There are

m

white &

n

black balls in the first urn and

p

white &

q

black balls in the second urn. One ball is taken from the first urn & placed into the second. Now, the probability of drawing a white ball from the second urn is

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IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 2>Q 20

In a bolt factory, machines

X, Y, Z

manufacture bolts that are respectively

25 %, 35 %

and

40 %

of the factory's total output. The machines

X, Y, Z

respectively produce

2 %, 4 %

and

5 %

defective bolts. A bolt is drawn at random from the product and is found to be defective. What is the probability that it was manufactured by machine

X

HARD

JEE Main

IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 2>Q 21

A student answers a multiple choice question with

5

alternatives, of which exactly one is correct. The probability that he knows the correct answer is

p, 0 < p < 1

. If he does not know the correct answer, he randomly ticks one answer. Given that he has answered the question correctly, the probability that he did not tick the answer randomly, is

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JEE Main

IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 2>Q 22

The probability distribution of a discrete random variable $X$ is given by

$X = x$	$- 1$	$0$	$1$	$2$
$P (X = x)$	$\frac{1}{3}$	$\frac{1}{6}$	$\frac{1}{6}$	$\frac{1}{3}$

Then, the value of $6 E (X^{2}) - V a r (X)$ is

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JEE Main

IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 2>Q 23

A box contains

6

pens,

2

of which are defective. Two pens are taken randomly from the box. If a random variable

X

is the number of defective pens obtained, then standard deviation of

X =

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JEE Main

IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 2>Q 24

An ordinary die is rolled in a certain number of times. The probability of getting an odd number

2

times is equal to the probability of getting an even number

3

times. Then, the probability of getting an odd number on an odd number of times, is

HARD

JEE Main

IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 2>Q 25

The records of a hospital show that

10 %

of the cases of a certain disease are fatal. If six patients are suffering from the disease, then the probability that only three will die is equal to

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IMPORTANT

Mathematics Crash Course JEE Main>Chapter 23 - Probability>Level 3>Q 8

Two aeroplanes I and II bomb a target in succession. The probability of I and II scoring a hit correctly are

0.3

and

0.2

, respectively. The second plane will bomb only if the first misses the target. The probability that the target is hit by the second plane is

A coin is tossed until a head appears or it has been tossed thrice. Given that head doesn't appear on the first toss, the probability that coin tossed thrice is

Important Questions on Probability

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