Aptitude - Probability - Discussion

Discussion Forum : Probability - General Questions (Q.No. 7)

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:

117

Answer: Option

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

Discussion:

54 comments Page 6 of 6.

Priya said: 1 decade ago

1050/2300 = 21/46.

RAJA said: 1 decade ago

Very good sanjana.

Kuldeep said: 8 years ago

Thanks @Sanjana.

Swetha said: 1 decade ago

Thanks sanjana.

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