Quantitative Aptitude - Permutation And Combinations

Avatto > > Bank Exam > > Practice Questions > > Quantitative Aptitude > > Permutation And Combinations

21. There are (n + 1) white and (n + 1) black balls each set numbered 1 to n + 1. The number of ways in which the balls can be arranged in a row so that adjacent balls are of diferent colours, is

Cancel reply

Your email address will not be published. Required fields are marked *


Cancel reply

Your email address will not be published. Required fields are marked *


22. Number n of license plates that can be made where each plate contains two distinct letters followed

  • Option : B
  • Explanation : n = 26 x 25 x 10 x 9 x 8=468000. i.e. there are twenty-six choices for the first letter, but only twenty-five choices for the second letter which must be different from the first letter. Similarly, choices for the digits are 10, 9 and 8 since the digits must be distinct.
Cancel reply

Your email address will not be published. Required fields are marked *


Cancel reply

Your email address will not be published. Required fields are marked *


23. Suppose a licence plate contains two letters followed by three digits with the first digit not zero. How many different licence plates can be pinted?

  • Option : C
  • Explanation : Each letter can be printed in twenty-six different ways, the first digit in nine ways and each of the other two digits in ten ways. Hence 26 x 26 x 9 x 10 x 10 = 608400 different plates can be printed.
Cancel reply

Your email address will not be published. Required fields are marked *


Cancel reply

Your email address will not be published. Required fields are marked *


 

Common data  for next 2 questions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Given : npr = 3024.

24. Value of n will be

  • Option : D
  • Explanation : Since np is product of consecutive positive integers, npr=3024=9x8x7x6 Hence n=9 and r = 4
Cancel reply

Your email address will not be published. Required fields are marked *


Cancel reply

Your email address will not be published. Required fields are marked *


25. Value of r will be

  • Option : B
  • Explanation : Since np is product of consecutive positive integers, npr=3024=9x8x7x6 Hence n=9 and r = 4
Cancel reply

Your email address will not be published. Required fields are marked *


Cancel reply

Your email address will not be published. Required fields are marked *