Arecipe for 60 cookies calls 4 cups of flour. how much flour is needed for 90 cookies

I'm pretty sure that the answer would be 6 cups of flour.
This is because 60 divide by 4 equals to 15 (60/4=15) so now divide 90 by 15 which will then equal to 6. (90/15=6)
So the flour needed to make 90 cookies would be 6 cups of flour.
Hope this helps

6 cups of flower because 1/3 of 90 is 30 and 60 = 4 cups so 2 cups per 30