Question

1. In how many ways 10 persons can be arranged such that 3 are always together?​

Answer 1

Answer:

Haven't studied permutation and combinatorics yet.

To find no. of ways,

nCr = n!/(n-r)! * r!

This is the formula

10C3 = 10!/3!*7!

= 10*9*8/3*2

= 120 ways.

I am in class 9

I am not sure if this is correct.