Answer:
There were 140 M&M's in the bag to start.
Step-by-step explanation:
Note: The word "of" is a good indicator of multiplication in word problems.
Let's say x is the number of M&M's in the bag. Then,
21=x*15%
Solve for x by dividing by 15% on both sides
140=x
There were 140 M&M's in the bag to start.
