Question

If a computer network has 60 switching nodes, in how many ways can 2 or 3 nodes fail?___________

Answer 1

There are 35990 ways in which 2 or 3 nodes fail

Explanation:

Given : A computer network has 60 switching nodes.

To Find : In how many ways can 2 or 3 nodes fail?

Solution:

We are supposed to find no. of ways can 2 or 3 nodes fail.

So, we will use combination here .

No. of ways can 2 or 3 nodes fail=
`^(60){C_2 +^(60)C_3`

Formula :
`^nC_r =(n!)/(r!(n-r)!)`

No. of ways can 2 or 3 nodes fail=
`(60!)/(2!(60-2)!)+(60!)/(3!(60-3)!)`

=
`35990`

Hence there are 35990 ways in which 2 or 3 nodes fail