Answer: 37 albums
Explanation:
Question wants to know the number of albums sold last month.
He is paid $200 base rate every month so we need to remove this to find out the total he made from album sales:
= 644 - 200
= $444
If he made $444 from album sales when he got $12 per album, the total number of albums sold is:
= 444 / 12
= 37 albums