if a recipe uses 2/3 tablespoons of salt for every 3/4 cup of flour and I have 3 cups of flour how much salt do I need?

Question

Need help figuring out the conversion on this one

Answer 1

This is a ratio problem 

 

2/3 is to 3/4 as X is to 3

 

2/3:3/4 :: X:3

 

You can multiply all the numbers in the ratio by 12 to clear the fractions 

 

8:9 :: 12X:36

 

In fraction form this is 

 

8/9 = 12X/36 

 

Cross multiply to get 

 

108X = 288

X = 288/108 = 8/3 = 2 2/3 tablespoons of salt 

 

Check:  3 cups of flour is 4 times as much as 3/4 cup

            8/3 tablespoons of salt is 4 times as much as 2/3 tablespoons