Apet store sells angle fish for $6 each and clown fish for $4 each. if the pet store sold fish for $36, how many of each type did they sell?

There are four possibilities...but first does the problem tell you how many total fish were sold?

If not the possible combinations are:

0 angel and 9 clownfish
2 angel and 6 clownfish
4 angel and 3 clownfish
6 angel and 0 clownfish