Hermione went to a pet store and bought a fish tank that cost $62.00 plus 5% sales tax. She gave the clerk $100.00. How much change should she receive?
A $43.00
B $38.00
C $34.90
D $33.00

If i think this is what your asking, he should look at the grams or pounds/ounces and compare the to their cost then max can identify which one is proportional and which is not ( i think xd)