Search any question & find its solution
Question:
Answered & Verified by Expert
The number of ways in which $\mathrm{n}$ boys and $\mathrm{n}$ girls can be arranged in a row such that all the boys are together and all the girls are also together is equal to
Options:
Solution:
1383 Upvotes
Verified Answer
The correct answer is:
none of these
Making 2 groups of $n$ girls and $n$ boys and arrange them $=n ! \cdot n ! \times 2 !$
Now number of ways to arrange $n$ boys and $n$ girls no two girl or boy are together.
Arrange $n$ boys alternately in $n$ ! ways there will be $(n+1)$ gaps, select $n$ gaps in them and arrange girls by ${ }^{n+1} P_n \times n !$ ways $=(n+1) ! \times n !$
Now number of ways to arrange $n$ boys and $n$ girls no two girl or boy are together.
Arrange $n$ boys alternately in $n$ ! ways there will be $(n+1)$ gaps, select $n$ gaps in them and arrange girls by ${ }^{n+1} P_n \times n !$ ways $=(n+1) ! \times n !$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.