A whole number is added to 25 and the same number is subtracted from 25. The sum of the resulting numbers is
Let the whole number = a
First number = 25 + a
Second number = 25 - a
Sum of resulting numbers = 25 + a + (25 - a)
= 25 + a + 25 - a
= 25 + 25 + a - a
= 50 + 0
= 50