Curioustab

Home » Aptitude » Probability

In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:

21 46
25 117
1 50
3 25

Correct Answer: 21 46

Explanation:

Let S be the sample space and E be the event of selecting 1 girl and 2 boys.

Then, n(S)

= Number ways of selecting 3 students out of 25

= ²⁵C₃ `

=	(25 x 24 x 23)
	(3 x 2 x 1)

= 2300.

n(E)

= (¹⁰C₁ x ¹⁵C₂)

=	[	10 x	(15 x 14)	]
			(2 x 1)

= 1050.

∴ P(E) =	n(E)	=	1050	=	21	.
	n(S)		2300		46

← Previous Question Next Question→

More Questions from Probability

From a pack of 52 cards, two cards are drawn together at random. What is the probability of both the cards being kings?
A bag contains 6 black and 8 white balls. One ball is drawn at random. What is the probability that the ball drawn is white?
In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?
Three unbiased coins are tossed. What is the probability of getting at most two heads?
A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
In a lottery, there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize?
What is the probability that a number selected from the numbers 1, 2, 3, 4, 5....16 is a prime number?
An urn contains 9 red, 7 white and 4 black balls. A ball is drawn at random. What is the probability that the ball drawn is not red?
In a lottery there are 20 prizes and 15 blanks. What is the probability of getting prize?
The odds in favour of an event are 3 : 5. The probability of occurrence of the event is?

Discussion & Comments

No comments yet. Be the first to comment!

Join Discussion