Answer:
$8.85
Step-by-step explanation:
This a question of direct variation, so we can make out a relationship between the two factors. 12 is 2/3 of 18, so the cost of 12 would also be 2/3 of the cost of 18. We can now make an equation to solve.
[tex]\frac{2}{3} x=5.9\\2x=17.7\\x=8.85[/tex]
