Question

You need to put your reindeer, Lancer, Gloopin, Rudy, and Bloopin, in a single-file line to pull your sleigh. However, Gloopin and Rudy are best friends, so you have to put them next to each other, or they won't fly.
How many ways can you arrange your reindeer?

Answer 1

Given :

Numbers of reindeer = 4

and we can't part Gloopin and Rudy .

To find :

Number of ways in which reindeer can be arranged .

Solution:

Numbers of places = 4

Gloopin and Rudy can't be parted from each other . Make them a group .

Now, we have to arrange Lancer , ( Gloopin , Rudy ) , Bloopin .

They can be arranged in 3! ways .

Gloopin and Rudy can also be arranged in 2! ways .

Number of ways in which reindeer can be arranged = 3! * 2! = 12