15. A baker is using a cookie recipe that calls for 2 ¼ cups of flour to yield 36 cookies. How much flour will the baker need to make 90 cookies using the same recipe?
Answer: B
The baker will need 6 ¼ cups of flour to make 90 cookies.
To determine the amount of flour needed for 90 cookies, the baker must scale the original recipe, which requires 2 ¼ cups of flour for 36 cookies. By calculating the proportion based on the desired quantity, it is found that the baker will need 6 ¼ cups of flour.
A) 5 ¼ cups
This option is incorrect. While it is a plausible amount of flour, it does not account for the necessary scaling from the original recipe to reach 90 cookies. The calculations show that more flour is required than this amount.
B) 6 ¼ cups
This is the correct answer. To find how much flour is needed for 90 cookies, one can set up a proportion based on the original recipe: (90 cookies / 36 cookies) * 2 ¼ cups = 6 ¼ cups of flour. This accurately reflects the scaling of ingredients needed.
C) 4 ¼ cups
This option is incorrect as it underestimates the amount of flour needed for 90 cookies. The calculations reveal that 4 ¼ cups is too little to yield the desired quantity based on the original recipe's ratio.
D) 10 ¼ cups
This option is also incorrect, as it significantly overestimates the amount of flour required. The baker needs to use a proportionate amount, and this figure exceeds the necessary calculations for 90 cookies.
Conclusion
The calculations confirm that 6 ¼ cups of flour is the precise amount needed for the baker to make 90 cookies, based on the original recipe's ratio. Other options either fall short or exceed this requirement, demonstrating that they are not viable choices in this context.