求助一道PREP题， 很急

zhang200824

96.
            10591-!-item-!-187;#058&007292

    

According to the directions on a can of frozen orange juice
concentrate, 1 can of concentrate is to be mixed with 3 cans of water to make
orange juice.  How many 12-ounce cans of
the concentrate are required to prepare 200 6-ounce servings of orange juice?

    

(A)  25

    

(B)  34

    

(C)  50

    

(D)  67

    

(E)  100

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解释里是200/ (3+1)很是不解， 帮解释下， 很着急谢谢