Question

The middle number of 3 consecutive whole numbers is 2a.

prove that the sum of these three numbers cannot be 250.

Answer 1

first number --- (2a-1)
middle number ---- (2a)
third number -----(2a+1)
2a-1+2a+2a+1=250
6a=250
a=250/6= 125/3
2a=2*(125/3)= 250/3 ---- is not a whole number that is contradicts to what is given, so sum cannot be 250
so