Question

The mean of five numbers is 27. If one number is excluded, their mean is 25. Find the
excluded number.

Answer 1

The mean of the numbers 27
The, sum of five numbers =  5 × 27

                                      = 135.

If one number is excluded, then the new mean is 25
∴ Sum of numbers 4× 25 =100  
∴Excluded number 135 -100 
   =35