Question

Store A is offering two tubes of lip gloss for $7. The costs for lip gloss at Store B are shown in the table. Assume the cost for the lip gloss varies directly with the number of tubes. At which store does the lip gloss cost more? Explain.

Answer 1

Hi,

I think this is the table, correct?

Number of Tubes 3 5 7

Cost ($) 12 20 28

we can calculate the prize as the number of tubes multiplied by 4:
3*4=12
5*4=20
7*4=28

which means that one tube costs 4 dollars!

However, in the store A two tubes cost 7, which means that one costs half of this -3.5

So Store B is more expensive (4 dollars per 4 rather than 3.5 as in Store A).