Chris mixed 3 pounds of raisins with 3 pounds of nuts. If a pound of nuts costs 3 times as much as a pound of raisins, then the total cost of the raisins was what fraction of the total cost of the mixture?	Choose the correct answer
A) 1 / 7  B) 1 / 5  C) 1 / 4  D) 1 / 3  E) 3 / 7

Rationale: "1 lbs of raisin = $ 1 3 lbs of raisin = $ 3 1 lbs of nuts = $ 3 3 lbs of nuts = $ 9 total value of mixture = 9 + 3 = 12 fraction of the value of raisin = 3 / 12 = 1 / 4 ans : c"
Answer: C