Question

five person are to address a meeting. If a specified speaker is to speak before another specified speaker,find the number of ways in which this can be arranged?

Answer 1

Suppose we choose any two person out of five people that we have.

So, that becomes 5C2
Now, they can be arranged in only 1! way because , their order to speak is already specified.

Now the remaining three speakers can be arranged in 3! ways.

So, the number of favourable ways = 5C2 * 1! * 3! = 10*1*6 = 60 ways.

Answer 2

Answer:

Suppose we choose any two person out of five people that we have.

So, that becomes 5C2

Now, they can be arranged in only 1! way because , their order to speak is already specified.

Now the remaining three speakers can be arranged in 3! ways.

So, the number of favourable ways = 5C2 * 1! * 3! = 10*1*6 = 60 ways.