# Finite math help?

1. Nov 13, 2004

### demongrl2204

finite math help??

Just need a clue of how to start this problem (kinda confused with the ratios)
I know what the answer is, (from back of book)just need to know how to set it up in order to do other problems??
**Each ounce of substance A supplies 5% of the nutrition a patient needs. Substance B supplies 12% of the required nutrition per ounce. If digestive restrictions require that the ratio of substance A to Substance B be 3/5, how many ounces of each should be in the diet to provide 100% of the required nutrition??**

thanks for any help!!??

2. Nov 13, 2004

### arildno

Welcome to PF!
Try set up a system of equations:
Let "x" be the number of ounces of "A", "y" the number of ounces of B.
What relations between "x" and "y" have you been given?

3. Nov 13, 2004

### demongrl2204

I understand how to do the equation type problems, but this one just didn;t make sense to me, cause that's all the information it gives and i seems like it isn't enough or you have to do something with the 3/5 ration btw A and B and I don't understand how to do that??

4. Nov 13, 2004

### shmoe

You should be able to get two equations out of the problem, one involving the total amount of nutrition consumed, the other involving the ratio bit you are having trouble with.

The ratio of substance A to substance B is the number of ounces of A divided by the number of ounces of B, e.g. if you had 10 ounces of A and 3 ounces of B this would be 10/3. The requirement that this ratio is 3/5 gives you your second equation.

Can you set up these two equations? What do you get?