Respuesta :

Answer:

33%

Step-by-step explanation:

Find the increase in salary...

$40,000 - $30,000 = $10,000 increase

Find out how much %  that was from his original salary...

10,000/30,000 = 0.333333333

So it was a 33.33333%, here they just rounded it down to 33%

33% is the right answer to it.