1000 meters make 1km. So let's compare that with the question.
1000m=1km
Y=33km
I represented the unknown with Y. Next, you have to cross and multiply. 33 will multiply 1,000 to give 33,000. And Y will multiply 1 to give Y. That will be;
Y=33,000m
33km makes 33,000m.
Hope that helped. Have a nice day