SOLUTION: An oatmeal cookie recipe calls for 1/2 cup of butter to make 6 dozen cookies. Hilda needs to make 15 dozen cookies for the bake sale. How many cups of butter will she need?

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Question 1139685: An oatmeal cookie recipe calls for
1/2 cup of butter to make 6 dozen cookies. Hilda needs to make 15 dozen cookies for the bake sale. How many cups of butter will she need?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

1/2 = 0.5

We know that 1/2 cup of butter makes 6 dozen cookies, so if x cups of butter make 15 dozen cookies, then we have the proportion 0.5/6 = x/15. I'm using 0.5 in place of 1/2 as it makes the equation more readable.

Let's solve for x
0.5/6 = x/15
0.5*15 = 6*x ..... cross multiply
7.5 = 6*x
6x = 7.5
6x/6 = 7.5/6 ..... divide both sides by 6
x = 1.25
x = 1 + 0.25
x = 1 + 1/4 ...... convert 0.25 to a fraction
x = 1 & 1/4

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Answer: 1 & 1/4 cups of butter

This is a mixed number and it is read as "one and a quarter" or as "one and one-fourth". You can write it as 1.25, though the convention in cooking is to use a mixed number format. Possibly because many people can picture what "fourths" represent rather than the decimal 0.25.