Q. 8 C3.8( 5 Votes )

# How many different selections of 4 books can be made from 10 different books, iftwo particular books are never selected.

It is told that two books are never selected.

It is similar to selecting 4 books out of remaining 8books as 2 books are already removed.

Let us assume the choosing the no. of ways be N2,

N2 = choosing 4 books out of 8 books

N2 = 8C4

We know that

And also n! = (n)(n – 1)(n – 2)…………2.1

N2 = 70 ways

The required no. of ways are 210, 28, 70.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Permutations & Combinations | Analyze your learningFREE Class
Challenging Quiz on P&C | Test Yourself55 mins
Check Your progress Part 2| Interactive Quiz: Permutation & Combination54 mins
Understand Permutations like never before60 mins
Lecture on Combinations49 mins
Interactive Quiz on Division and distribution of objects17 mins
Interactive Quiz on Combinations50 mins
Lets see how good you can manage numbers | P&C Quiz Challenge41 mins