Question

13. The mean of five number is 18. If one number is excluded, their mean is 6. Find the excluded number.​

Answer 1

Answer:

66

Step-by-step explanation:

Let the nos be a,b,c,d,e and e is the excluded no.

(a+b+c+d+e)/5 = 18

=> a+b+c+d+e = 90

And,

(a+b+c+d)/4 = 6

=> a+b+c+d = 24

Therefore, e = 90- 24 = 66

Answer 2

Step-by-step explanation:

Mean of 5 numbers =18

⇒ Sum of these 5 numbers =18×5=90

Let  the number that has been excluded be x

New mean =  

4

90−x

​

=16

Solving this, we get

90−x=64

∴x=26