Question

Find the number of arranging 11 distinct
objects taken 4 at a time so that a specified
object.
(a) always occurs (b) never occurs.

Answer 1

The answer for particular thing to always occur is [(10 P^3) x 4] = (720 x 4) = 2880.

Answer for thing to never occur is (10 P^4) = 5040

Step-by-step explanation:

First case:

• By selecting and arranging 4 out of 11 things, one of them will always occur.  
• Now, if one of them will always occur, then you have 10 things left and you can choose only 3 more things now.
• The answer is (10 P^3) x 4 = 720 x 4 = 2880
• “10 P^3″ for 3 different things to be arranged, and "4″ for arrangement of the thing which will always occur.

Second case:

• If one particular thing will never occur. You have to select 4 out of 10 things now, since one of them will never occur.

• So, answer is (10 P^4) = 5040

Also learn more

What is a probability?

https://brainly.in/question/3061058

Answer 2

Hope it is useful for you