Home
Class 11
MATHS
The number of ways in which m+n(nlem+1) ...

The number of ways in which `m+n(nlem+1)` different things can be arranged in a row such that no two of the n things may be together, is

A

`((m+n)!)/(m!n!)`

B

`(m!(m+1)!)/((m+n)!)`

C

`(m!(m+1)!)/((m-n+1)!)`

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem of arranging \( m+n \) different things in a row such that no two of the \( n \) things are together, we can follow these steps: ### Step-by-Step Solution 1. **Arrange the \( m \) things**: First, we arrange the \( m \) different things. The number of ways to arrange \( m \) things is given by \( m! \). **Hint**: Remember that the arrangement of \( m \) distinct items is calculated using factorial notation. 2. **Identify the gaps for \( n \) things**: After arranging the \( m \) things, there will be \( m + 1 \) gaps where the \( n \) things can be placed. This includes one gap before the first item, one gap after the last item, and \( m - 1 \) gaps between the \( m \) items. **Hint**: Visualize the arrangement of \( m \) items to see where the gaps are located. 3. **Choose gaps for \( n \) things**: We need to choose \( n \) gaps from the \( m + 1 \) available gaps to place the \( n \) things. The number of ways to choose \( n \) gaps from \( m + 1 \) is given by \( \binom{m+1}{n} \). **Hint**: Use the combination formula \( \binom{n}{r} = \frac{n!}{r!(n-r)!} \) to calculate the number of ways to choose gaps. 4. **Arrange the \( n \) things**: Once we have chosen the gaps, we can arrange the \( n \) things in those gaps. The number of ways to arrange \( n \) things is given by \( n! \). **Hint**: Factorial notation applies here as well since the arrangement of distinct items is involved. 5. **Combine the results**: The total number of arrangements is the product of the number of ways to arrange the \( m \) things, the number of ways to choose the gaps, and the number of ways to arrange the \( n \) things. Therefore, the total number of arrangements is: \[ \text{Total arrangements} = m! \times \binom{m+1}{n} \times n! \] 6. **Final expression**: Substituting the combination formula into the total arrangements gives: \[ \text{Total arrangements} = m! \times \frac{(m+1)!}{n!(m+1-n)!} \times n! \] Simplifying this, we find: \[ \text{Total arrangements} = \frac{(m+1)!}{(m+1-n)!} \times m! \] ### Final Answer Thus, the number of ways in which \( m+n \) different things can be arranged in a row such that no two of the \( n \) things are together is: \[ \frac{(m+1)!}{(m+1-n)!} \times m! \]
Promotional Banner

Topper's Solved these Questions

  • PERMUTATIONS AND COMBINATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|60 Videos
  • PERMUTATIONS AND COMBINATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section II - Assertion Reason Type|9 Videos
  • PARABOLA

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|30 Videos
  • PROBABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|45 Videos

Similar Questions

Explore conceptually related problems

Number of ways in which 12 different things can be distributed in 3 groups, is

Find the number of ways by which 4 green, 3 red and 2 white balls can be arranged in a row such that no two balls of the same colour are together. All balls of the same colour are identical.

Number of ways in which 5 plus (+) signs and 5 minus (-) signs be arranged in a row so that no two minus signs are together is

The total number of ways in which six '+' and four '-' signs can be arranged in a line such that no two signs '-' occur together, is ……….. .

The number of ways in which 5 boys and 3 girls can be seated in a row, so that no two girls sit together is

Show that the number of ways in which p positive and n negative signs may be placed in a row so that no two negative signs shall be together is (p+1)C_n .

Find the numbers of ways in which 5 girls and 5 boys can be arranged in a row if no two boys are together.

Find the number of ways in which 5 boys and 3 girls can be seated in a row so that no two girls are together.

Find the total number of ways in which six '+' and four '-' signs can be arranged in a line such that no two '-' signs occur together.

The number of ways in which letter of the word '"ARRANGE"' can be arranged, such that no two R's are together, is

OBJECTIVE RD SHARMA ENGLISH-PERMUTATIONS AND COMBINATIONS-Exercise
  1. The number of all four digit numbers which are divisible by 4 that can...

    Text Solution

    |

  2. The number of all five digit numbers which are divisible by 4 that can...

    Text Solution

    |

  3. The number of ways in which m+n(nlem+1) different things can be arrang...

    Text Solution

    |

  4. All possible two-factor products are formed from the numbers 1, 2,…..,...

    Text Solution

    |

  5. m men and n women ae to be seated in a row so that no two women sit...

    Text Solution

    |

  6. Find the number of ways in which six '+' and four '-' signs can be arr...

    Text Solution

    |

  7. If in a chess tournament each contestant plays once against each of th...

    Text Solution

    |

  8. Total number of four digit odd numbers that can be formed by using 0, ...

    Text Solution

    |

  9. A committee of 5 is to be formed from 9 ladies and 8 men. If the commi...

    Text Solution

    |

  10. The number of ordered triplets, positive integers which are solutions ...

    Text Solution

    |

  11. Find the number of straight lines that can be drawn through any two po...

    Text Solution

    |

  12. The number of ways in which 10 candidates A1,A2, A(10) can be rank...

    Text Solution

    |

  13. , the number of ways in which 10 candidates A(1)andA(2) can be ranked ...

    Text Solution

    |

  14. The total number of all proper factors of 75600, is

    Text Solution

    |

  15. The total number of ways in which 11 identical apples can be distribut...

    Text Solution

    |

  16. Number of ways in which a pack of 52 playing cards be distributed equa...

    Text Solution

    |

  17. (i) In how many ways can a pack of 52 cards be divided equally a...

    Text Solution

    |

  18. The total number of ways of dividing 15 different things into groups o...

    Text Solution

    |

  19. There are three copies each of 4 different books. In how many ways can...

    Text Solution

    |

  20. The number of ways in which 12 books can be put in three shelves wi...

    Text Solution

    |