Two Arrangements | PRMO 2019 | Question 5

Five persons wearing badges with numbers 1,2,3,4,5 are seated on 5 chairs around a circular table. Find the number of ways they be seated that no two persons whose badges have consecutive numbers are seated next to each other.

Here they may seat in circular way such that 1,3,5,2,4 and again 1

then they may seat in another circular way 1,4,2,5,3 and again 1

Then number of ways = (2)(5) =10.

Subscribe to Cheenta at Youtube