Question

The mean of 5 numbers is 27.If one more number is included,then their mean becomes 25.Find the included number.

Answer 1

Answer:

mean =  toal sum of numbers/ total no.

     27 = total sum of numbers / 5

==> 27*5 = total sum of number

==> 135 = total sum of number

when 1 more number is added

so,

mean =  toal sum of numbers/ total no.

25  =  toal sum of numbers/ 6

25*6 =  toal sum of numbers

toal sum of numbers = 150

so, the number is = 150-135 ==> 15

Answer 2

the mean of 5 number= 27
the sum of the number = mean × no.of number

the sum of number = 27×5
=135
then, one number is included. So,

the mean of 5+1 number = 25
the sum of numbers = 6×25
= 150
the included number= the sum of 6 number- the sum of 5 numbers
the number = 150-135
=15

answer: the included number is 15