Help me solve this GMAT Quant Question (GMATPrep) #5

According to the direction 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 of the concentrate are required to prepare 2006-ounce serving of orange juice.

A)25
B)34
C)50
D)67
E)100

OAA

This can be solved using equivalent ratios.
The first part tells that, for every 1 can of concentrate, we can make 4 cans of juice.
Let's be even more generic, for 1 volume of concentrate, we can make 4 volumes of juice.

Okay, now notice that we have a problem with the volume mismatch in the question. It involves 12-ounce cans of concentrate and 6-ounce servings.
So, let's reword the question. Instead of making 200 6-ounce servings of juice, let's make 100 12-ounce servings of juice. We're still making the same amount of juice.

We're now asking, "How many 12-ounce cans of the concentrate are required to prepare 100 12-ounce serving of orange juice?

We'll solve this question using equivalent ratios.

(volume of concentrate)/(volume of juice): 1/4 = x/100

Solve for x to get [spoiler]x=25[/spoiler]
So, the answer is A

Cheers,
Brent

Hi EricImasogie,

One of the great aspects about most GMAT questions is that they can be approached in a variety of ways. Here, even the "math approach" can be done in a number of different ways. Here's another:

To start, we're given a "recipe" for making orange juice: 1 can of concentrate + 3 cans of water = 4 CANS of juice

Next, we're told that each "can" = 12 ounces. Combined with the prior info (above)....

1 can of concentrate + 3 cans of water = 4 cans of juice = 48 OUNCES of juice

We're told to make 200 6-ounce servings of juice, which is 200(6) = 1,200 ounces of juice. The question asks how many cans of CONCENTRATE are needed to get us 1,200 ounces (according to the recipe).

Since 1 can of concentrate --> 48 ounces of juice, we can do division to figure out the number of cans needed:

1200/48 = 25 cans of concentrate

Final Answer: A

GMAT assassins aren't born, they're made,
Rich