Jeremiah Whitney

Mathematics

22 July, 22:00

Three tubes of brand A toothpaste cost $12, five tubes of brand B toothpaste cost $25, and eight tubes of brand C toothpaste cost $32. Is the relationship between the number of tubes of toothpaste and the cost a proportional relationship? If it is, give the constant of proportionality assuming that cost depends on the number of tubes bought.

A. The relationship is proportional. The constant of proportionality is $4 per tube.

B. The relationship is proportional. The constant of proportionality is $5 per tube.

C. The relationship is proportional. The constant of proportionality is $12 per tube.

D. The relationship is not proportional.