Answer:
$15.75
Step-by-step explanation:
Let the cost of 7 gallons of milk be x
Since
3 gallons of milk = $6.75
7 gallons of milk = x
Cross multiply
7 x 6.75 = 3 x X
47.25 = 3x
Divide both sides by 3
47.25/3 = 3x/3
15.75 = x
x = $15.75
7 gallons of milk cost $15.75
