4 is your answer have a nice day
It would be, 6.72/3 = $2.24
They both have the same rate of change
For this case we propose a system of equations:
x: Let the variable representing the quantity of Granny Smith apples
y: Let the variable representing the number of Gala apples
According to the statement we have:

From the first equation we have to:

replacing in the second equation:

So, Carl bought 7 Gala apples
On the other hand:

So, Carl bought 12 Granny Smith apples
Answer:
Carl bought 7 Gala apples and 12 Granny Smith apples