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3 Girls and 4 boys are to be seated in a row on 7 chairs in such a way that all the three girls always sit together. In how many different ways can it be done ?
- A720
- B576
- C144
- D480
Answer not set
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0
CCommunity
Solution
Total number of persons = 3 + 4 = 7
The girls always sit together.
Considering the three girls as 1 person, we have 5 persons which can be arranged in 5! ways
But corresponding to each way of these arrangements, the girls can be arranged together in 3! ways.
Hence, required number of words = $5! \times 3!$
= 120 * 6 = 720
Total number of persons = 3 + 4 = 7
The girls always sit together.
Considering the three girls as 1 person, we have 5 persons which can be arranged in 5! ways
But corresponding to each way of these arrangements, the girls can be arranged together in 3! ways.
Hence, required number of words = $5! \times 3!$
= 120 * 6 = 720
0
CCommunity
Solution
Total number of persons = 3 + 4 = 7
The girls always sit together.
Considering the three girls as 1 person, we have 5 persons which can be arranged in 5! ways
But corresponding to each way of these arrangements, the girls can be arranged together in 3! ways.
Hence, required number of words = $5! \times 3!$
= 120 * 6 = 720
Total number of persons = 3 + 4 = 7
The girls always sit together.
Considering the three girls as 1 person, we have 5 persons which can be arranged in 5! ways
But corresponding to each way of these arrangements, the girls can be arranged together in 3! ways.
Hence, required number of words = $5! \times 3!$
= 120 * 6 = 720