Answer: No, perry is not using the correct ratio.
Step-by-step explanation: The ratio used in the cafeteria is 15:17 if we calculate the quotient of these numbers, we have:
15/17 = 0.882
Now, the ratio that Perry is using is 5:7, the quotient now is:
5/7 = 0.713
You can see that the quotients are different, which means that the ratios are different.
Here we are dividing the number of cups of swiss cheese by the number of cups of cheddar cheese.
The fact that in the perry recipe the quotient is smaller, this means that in this recipe the swiss cheese has less presence than in the cafeteria recipe.
If you want to reduce the proportions, it is kinda hard because 17 is a prime number, so you won't have a whole number of cups of cheddar cheese.
so 15/3 = 5, this means that we also must divide 17 by 3.
Then, the correct ratio would be:
5:17/3
or 5:5.666