Hi All,

We're told that a certain punch contains grape juice, orange juice, and pineapple juice and no other ingredients in a ratio of 2:3:7 respectively and a bowl contains 156 total ounces of this punch. We're asked for the number of ounces of grape juice in the punch. This question can be approached in a number of different ways, including by just listing out the multiples until you get to the correct answer.

Based on the given ratio, we could have...
2 ounces grape juice + 3 ounces orange juice + 7 ounces pineapple juice --> 12 total ounces of punch

re: 2 + 3 + 7 = 12

Increasing each 'part' accordingly, we could have:
4 + 6 + 14 = 24 ounces of punch
6 + 9 + 21 = 36 ounces of punch
8 + 12 + 28 = 48 ounces of punch
Etc.

At this point, you should notice that we're increasing the total in 'sets' of 12 ounces, so we can divide 156 by 12.... 156/12 = 13 sets of 12 ounces. Each of those sets contains 2 ounces of grape juice, so we have (13)(2) = 26 ounces of grape juice in total.

Final Answer: B

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Rich

AAPL wrote:Princeton Review

A certain punch contains grape juice, orange juice, and pineapple juice and no other ingredients in a ratio of 2:3:7 respectively. If a bowl contains 156 ounces of this punch, how many ounces of grape juice does it contain?

A. 13
B. 26
C. 39
D. 91
E. 130

OA B

Since the ingredients are mixed in a ratio of 2:3:7, there are 2x ounces of grape juice, 3x ounces of orange juice, and 7x ounces of pineapple juice in this punch for some number x.

We can create the equation:

2x + 3x + 7x = 156

12x = 156

x = 13

So there are 2(13) = 26 ounces of grape juice in the punch.

Answer: B