If each dog eats three times as much as each cat, how much food would be needed to feed one meal to each 12 dogs and 20 cats?

Question

An animal shelter uses 18 cups of food to feed 20 dogs and 12 cats one meal each.

 

I tried this, but I got 6. 6 is a wrong answer. Please help. Thank you!!

Answer 1

18 cups for 20 dogs and 12 cats

a dog eats 3 times as much as a cat

20*3+12*1=72 servings for 20 dogs and 12 cats

18/72=1/4 cup

1/4 cup for each cat and 3/4 cup for each dog

12 dogs eat 12*(3/4) cups

20 cats eat 20*(1/4) cup

12*(3/4)=9 cups

20*(1/4)=5 cups

9+5=14 cups of food to feed 12 dogs and 20 cats