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From a group of three boys and four girls, a school hallway monitor gr

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From a group of three boys and four girls, a school hallway monitor gr [#permalink]

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From a group of three boys and four girls, a school hallway monitor group is to be selected. If the group is to be formed of one boy and three girls, how many different such groups can be formed?

A. 4
B. 12
C. 36
D. 72
E. 288
[Reveal] Spoiler: OA

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Kudos [?]: 133141 [0], given: 12415

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Re: From a group of three boys and four girls, a school hallway monitor gr [#permalink]

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New post 03 Apr 2017, 02:13
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Bunuel wrote:
From a group of three boys and four girls, a school hallway monitor group is to be selected. If the group is to be formed of one boy and three girls, how many different such groups can be formed?

A. 4
B. 12
C. 36
D. 72
E. 288


one boy can be selected from 3 boys in 3 ways
3 girls can be selected from 4 girls in 4C3 = 4 ways

the total number of ways in which the groups can be formed = 3*4 =12

Hence option B is correct
Hit Kudos if you liked it 8-)

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Re: From a group of three boys and four girls, a school hallway monitor gr [#permalink]

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New post 03 Apr 2017, 04:31
Option B

Out of 3 Boys and 4 Girls, a group of 1 Boy and 3 Girls can be formed in 3C1 x 4C3 = 12 ways
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Kudos [?]: 58 [0], given: 90

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Re: From a group of three boys and four girls, a school hallway monitor gr [#permalink]

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New post 10 Nov 2017, 10:37
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Top Contributor
Bunuel wrote:
From a group of three boys and four girls, a school hallway monitor group is to be selected. If the group is to be formed of one boy and three girls, how many different such groups can be formed?

A. 4
B. 12
C. 36
D. 72
E. 288


Take the task of creating the hallway monitor group and break it into stages.

Stage 1: Select two boys for the group
Since the order in which we select the boys does not matter, we can use combinations.
We can select 2 boys from 3 boys in 3C2 ways (3 ways)
So, we can complete stage 1 in 3 ways

Stage 2: Select two girls for the group
We can select 3 girls from 4 girls in 4C3 ways (4 ways)
So, we can complete stage 2 in 4 ways

By the Fundamental Counting Principle (FCP), we can complete the two stages (and thus create the hallway monitor group) in (3)(4) ways (= 12 ways)

Answer: C

Note: the FCP can be used to solve the MAJORITY of counting questions on the GMAT. So, be sure to learn it.

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Kudos [?]: 2627 [0], given: 362

Re: From a group of three boys and four girls, a school hallway monitor gr   [#permalink] 10 Nov 2017, 10:37
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