SOLUTION: A recipe calls for 2/3 cups of white flour and 2 1/5 cups of whole wheat flour. How much flour do I need in total for my recipe? I have tried to solve the problem by making the

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: A recipe calls for 2/3 cups of white flour and 2 1/5 cups of whole wheat flour. How much flour do I need in total for my recipe? I have tried to solve the problem by making the      Log On


   

Question 295617: A recipe calls for 2/3 cups of white flour and 2 1/5 cups of whole wheat flour. How much flour do I need in total for my recipe?
I have tried to solve the problem by making the mixed fraction into an improper fraction and finding it's reciprocal. Next, I found the LCM and I added both fractions and came up with 37/33, but the teachers answer is 10/33. Could you please tell me what it is I am doing wrong?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
The recipe calls for two types of flour. The problem asks for the total amount of flour needed for the recipe. You should add the two numbers and the sum will be a mixed number.
2%2F3%2B2%2B+1%2F5=2%2F3%2B11%2F5=10%2F15%2B33%2F15=43%2F15=2%2B+13%2F15
You are both wrong.
Your teacher is multiplying by the reciprocal which is dividing
2+%2B1%2F5=11%2F5
%282%2F3%29%2A%285%2F11%29=10%2F33
This is less than the 2%2F3 of white flour which would be 22%2F33.
Your answer 37%2F33+or 1%2B+4%2F33 is less than the 2+%2B1%2F5 cups of whole wheat flour.
I have no idea how you got that number.