Home
Class 12
MATHS
A total of 6 Boys and 6 girls are to sit...

A total of 6 Boys and 6 girls are to sit in a row alternatively and in a circle. Let m be the number of arrangements in the row and n be the number of arrangements in the circle. If `k=(m)/(10_(n))`, then the value of k is

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to calculate the number of arrangements of 6 boys and 6 girls sitting alternately in both a row and a circle. We will denote the number of arrangements in a row as \( m \) and in a circle as \( n \). We will then find the value of \( k = \frac{m}{10n} \). ### Step 1: Calculate the arrangements in a row (m) 1. **Arrangements in a row**: Since we need to arrange 6 boys and 6 girls alternately, we can start with a boy in the first position. The arrangement will look like this: \[ B G B G B G B G B G B G \] This means we have 6 positions for boys and 6 positions for girls. 2. **Permutations**: The number of ways to arrange 6 boys is \( 6! \) and the number of ways to arrange 6 girls is also \( 6! \). Therefore, the total arrangements when starting with a boy is: \[ 6! \times 6! \] 3. **Starting with a girl**: If we start with a girl, the arrangement will look like this: \[ G B G B G B G B G B G B \] The number of arrangements remains the same, \( 6! \times 6! \). 4. **Total arrangements in a row**: Since we can start with either a boy or a girl, we multiply the arrangements by 2: \[ m = 2 \times (6! \times 6!) = 2 \times 6! \times 6! \] ### Step 2: Calculate the arrangements in a circle (n) 1. **Arrangements in a circle**: When arranging in a circle, we can fix one person to eliminate the effect of rotations. Let's fix one boy in position. 2. **Remaining positions**: After fixing one boy, we have 5 boys and 6 girls left to arrange. The arrangement will look like this: \[ B G B G B G B G B G \] Now we have 5 boys and 6 girls to arrange in the remaining positions. 3. **Permutations**: The number of ways to arrange the remaining 5 boys is \( 5! \) and the number of ways to arrange 6 girls is \( 6! \). Therefore, the total arrangements in a circle when starting with a boy is: \[ 5! \times 6! \] 4. **Starting with a girl**: If we fix a girl instead, we will have the same number of arrangements: \[ 5! \times 6! \] 5. **Total arrangements in a circle**: Since we can start with either a boy or a girl, we multiply the arrangements by 2: \[ n = 2 \times (5! \times 6!) = 2 \times 5! \times 6! \] ### Step 3: Calculate k 1. **Substituting values**: Now we substitute \( m \) and \( n \) into the equation for \( k \): \[ k = \frac{m}{10n} = \frac{2 \times 6! \times 6!}{10 \times (2 \times 5! \times 6!)} \] 2. **Simplifying**: The \( 2 \) cancels out: \[ k = \frac{6! \times 6!}{10 \times 5! \times 6!} = \frac{6!}{10 \times 5!} \] 3. **Using factorial properties**: Since \( 6! = 6 \times 5! \): \[ k = \frac{6 \times 5!}{10 \times 5!} = \frac{6}{10} = \frac{3}{5} \] 4. **Final value**: Thus, the value of \( k \) is: \[ k = 1.2 \] ### Final Answer: The value of \( k \) is \( 1.2 \).
Promotional Banner

Similar Questions

Explore conceptually related problems

Let m denotes the number of ways in which 5 boys and 5 girls can be arranged in a line alternately and n denotes the number of ways in which 5 boys and 5 girls an be arranged in a circle so that no two boys are together . If m= kn then the value of k is :

6 boys and 6 girls sit in a row at random. Find the probability that all the girls sit together.

6 boys and 6 girls sit in a row at random. Find the probability that all the girls sit together.

In a classroom, the students have to sit in four rows. Find the rule for the number of students in the class if the number of students in each row is n.

Six identical coins are arranged in a row. The total number of ways in which the number of heads is equal to the number of tails is

Let there be 4 boys and 4 girls are standing in a row. If m is the number of ways in which all the girls are consecutive and n is the number of ways in which exactly 3 boys are consecutive. If p denotes the number of ways in which 5 men and 5 women stand in a row such that men and women are alternate, then the value of p/(m+n) is equal the ...

If a group of n distinct objects, the number of arrangements of 4 object is 12 times the number of arrangements of 2 objects, then the number of objects is (a) 10 (b) 8 (c) 6 (d) none of these

Three boys and three girls are to be seated around a table in a circle. Among them, the boy X does not want any girl neighbour and the girl Y does not want any boy neighbour. The number of such arrangements are possible is

12 boys and 2 girls are to be seated in a row such that there are atleast 3 boys between the 2 girls. The number of ways this can be done is lamdaxx12! . The value of lamda is

A group of 2n students consisting of n boys and n girls are to be arranged in a row such that adjacent members are of opposite sex. The number of ways in which this can be done is