Johnrohit wrote:Food C containd 20% protein by weight and 80% carbs. Food D contains 75% protein and 25% carbs by weight.In what ratio should Food C & D be mixed such that the resulting mix contains 45% of protein by weight? (ratios for C: D presented below)
A) 3:2
B)5:6
C)6:5
D)4:3
Protein in C = 20%.
Protein in D = 75%,
Protein in the MIXTURE of C and D = 45%.
The following approach is called ALLIGATION -- a very efficient way to handle MIXTURE PROBLEMS.
Step 1: Plot the 3 percentages on a number line, with the percentages for C and D on the ends and the percentage for the mixture in the middle.
C 20%-----------45%-----------75% D
Step 2: Calculate the distances between the percentages.
C 20%----
25-----45%----
30-----75% D
Step 3: Determine the ratio in the mixture.
The required ratio of C to D is equal to the RECIPROCAL of the distances in red.
C : D = 30:25 = 6:5.
The correct answer is
C.
For two similar problems, check here:
https://www.beatthegmat.com/ratios-fract ... 15365.html
An alternate approach is to PLUG IN THE ANSWERS.
Answer choice C: C : D = 6:5
6 parts 20% protein = 6*20 = 120.
5 parts 75% protein = 5*75 = 375.
Average per 11 parts = (120 + 375)/11 = 495/11 = 45%.
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