Bunuel wrote:
If 2 pounds of almonds that cost c dollars per pound are mixed with 4 pounds of peanuts that cost b dollars per pound and 5 pounds of cashews that cost 2c + b dollars per pound, what is the average (arithmetic mean) cost, in dollars, per pound of the mixture?
A. 11/(c + b)
B. 40/(b + c)
C. 11(c + b)/9
D. 12(b + c)/11
E. (12c + 9b)/11
Average cost per pound = 2*c+4*b+5*(2c+b)/11= 2c+4b+10c+5b/11 = 12c+9b/11
Ans:E
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