We have to find what 20% of $1,800 is.
We can do this by multiplying 0.20 and $1,800
Lets do that :)
0.20 x $1,800 = $360
Now we know that 20% of $1,800 is $360
Since it is asking for his new salary with an extra 20%
we add $1,800 and $360
Soo..
$1,800 + $360 = $2,160
This means that mark's new paycheck is $2,169
Good Luck! :)