Question

it is given that the mean of 5 numbers is 27 if one of the number is excluded, the mean gets reduced by 2,find the excluded number

Answer 1

Let the numbers be a,b,c,d,e
By the problem,(a+b+c+d+e)/5=27
So,a+b+c+d+e=27*5=135------(1)
Let the exclude number be 'a'
Then,(b+c+d+e)4=25
b+c+d+e=25*4=100-----------(2)
Substituting (2) in (1),
a+(100)=135
a=135-100=35
Therefore,the exclude number is 35.

Answer 2

27=x/5 where x is the sum of 5 numbers of the given mean                          x=135   but given that one no is excluded and mean is reduced by 2           therefore mean=27-2=25                                                                                25=y/4 where y is sum of numbers of mean after excluding one number     y=100                                                                                                              excluded number=x-y=135-100=35