Answer:
2 Cups of milk would be needed to bake 50 cookies
Explanation:
We can set this type of question up as a ratio. The problem states that for every 10 cookies 4/10 cups of milk is used therefore the ratio 10:4/10 can be created.
With the ratio created we have to get the 10 cookies to 50 cookies. Multiplying 10 by 5 will equal to 50, but with everything you do on one side of a ratio you need to do on the other side, therefore you need to multiply 4/10 by 5. 5*4/10 would then equate to 20/10. 20/10=2. There would be 2 cups of milk for 50 cookies.