**Solution**

: Let the first even number $=x$

Then, second even number $=x+2$

and third even number $=x+2+2=x+4$

According to question, $x+x+2+x+4=42$

or, $3 x+6=42$

or, $3 x=42-6=36$

or,

$x=\frac{36}{3}=12$

First even number $=12$

Second even number $=12+2=14$

Third even number $=12+4=16$