Which division problem does the number line below best illustrate?
m
1
4
5
6
7
8
9
10
O 10+2 = 5
15+3=5
50+5=10
O 20+10=2

If n stands for number sold and c stands for cost per item, in which column would you use the formula: ? a. column d c. column f b. column e d. column g