Question

You need 1 1/2 sticks of butter for every 24 cookies you bake how much butter will you need for 48 and 72 cookies?

Answer 1

Let x represent the amount of sticks of butter you need
First of all, we will find the amount of sticks of butter needs for 48 cookies by using Tree Diagram and Cross Multiply
1 1/2 sticks of butter:24 cookies
Or
3/2 sticks of butter:24 cookies
x sticks of butter:48 cookies
Use cross multiply
48*3/2=24*x
72=24x
Divided 24 to each side
72/24=24x/24
x=3 sticks of butter, so you will need 3 sticks of butter to make 24 cookies
Or
We know that 48 cookies is double 24 cookies. In conclusion, we know that the amount to make 48 cookies is double, so
1 1/2*2
=3/2*2
=3 sticks of butter

Next,
1 1/2 sticks of butter:24 cookies
x sticks of butter:72 cookies
Use cross multiply
1 1/2*72=24*x
3/2*72=24x
108=24x
Divided 24 to each side
108/24=24x/24
x=108/24
x=54/12
x=27/6
x=9/2
x=4.5 sticks of butter, so you will need 4.5 sticks of butter for 72 cookies. Hope it help!

Answer 2

1.5 sticks of butter for 24 cookies
48 / 24 = 2 1.5 * 2 = 3
3 sticks of butter for 48 cookies (double the cookies, double the butter)
72/24 = 3 1.5 * 3 = 4.5
4.5 sticks of butter for 72 cookies (triple the cookies, triple the butter)

24 = 3 sticks
72 = 4.5 sticks