You have not thought it through.
How to answer algebraically:
First integer is "x"
Add 2 to get the next even integer, it is "x+2"
And the third is "x+4"
We know the sum is 42, so we get the equation:
x+(x+2)+(x+4) = 42
3x = 36
x = 12.
So the first is 12, second is 14, and third is...