So, Anna has a markers, Ben has b markers and Cindy has c markers.
We know that a+b+c = m.
And we know also that a = 2b. ( twice as many markers as ben has)
(Remember b is the number of Ben markers.)
The equation becomes:
2b+b+c=m.
Solving for c:
[tex]c=m-3b[/tex]
Cindy has (m-3b) markers.
