I do not remember an exact question but the question language is as follows : XYZ was calculating the average of numbers from upto lets say 1000 . By mistake he missed out a number and the average came out to be “some value” . Find the number that…

I do not remember an exact question but the question language is as follows : XYZ was calculating the average of numbers from upto lets say 1000 . By mistake he missed out a number and the average came out to be "some value" . Find the number that was missed ? How can i solve this type of question and if anyone has an exact question do post it here .