Question:

From $6$ different novels and $3$ different dictionaries, $4$ novels and $1$ dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the number of such arrangements is

Updated On: Jul 28, 2022
  • less than 500
  • at least 500 but less than 750
  • at least 750 but less than 1000
  • at least 1000
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is D

Solution and Explanation

4 novels can be selected from 6 novels in $^6C_4$ ways. 1 dictionary can be selected from 3 dictionaries in $^3C_1$ ways. As the dictionary selected is fixed in the middle, the remaining 4 novels can be arranged in 4! ways. $?$ The required number of ways of arrangement $=^{6}C_{4}\times^{3}C_{1}\times4!=1080$
Was this answer helpful?
0
0

Top Questions on permutations and combinations

View More Questions

Concepts Used:

Permutations and Combinations

Permutation:

Permutation is the method or the act of arranging members of a set into an order or a sequence. 

  • In the process of rearranging the numbers, subsets of sets are created to determine all possible arrangement sequences of a single data point. 
  • A permutation is used in many events of daily life. It is used for a list of data where the data order matters.

Combination:

Combination is the method of forming subsets by selecting data from a larger set in a way that the selection order does not matter.

  • Combination refers to the combination of about n things taken k at a time without any repetition.
  • The combination is used for a group of data where the order of data does not matter.