In a certain pet shop, the ratio of dogs to cats to bunnies in stock i

Hi shasadou,

These types of ratio questions can be approached in a variety of ways, but this question includes some rather significant 'shortcuts' that you can take advantage of.

First off, the information about the cats is absolutely irrelevant. The information that matters is the ratio of dogs to bunnies and the TOTAL number of dogs and bunnies in the shop.

The ratio of dogs to bunnies is 3:11 - that means that there are MORE than 3 times as many bunnies as dogs.

For example
3 dogs and 11 bunnies = 14 total
6 dogs and 22 bunnies = 28 total
9 dogs and 33 bunnies = 42 total
etc.

Thus, whatever the total number of dogs and bunnies is, the number of dogs would be LESS than 1/4 of that total (see the above examples for proof). Here, the total number of dogs and bunnies is 196. Since the total number of dogs is LESS than 1/4 of 196, and the answer choices are rather 'spread out', you'll find that only one answer 'fits' that description...

Final Answer:

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

Here is a visual that should help.

We can create the following ratio:

dogs to cats to bunnies = 3x : 7x : 11x

Since the shop carries 196 dogs and bunnies total in stock, we ignore the cats and include only dogs and bunnies in our calculation:

3x + 11x = 196

14x = 196

x = 14

Thus, there are 3(14) = 42 dogs.

Answer: A

We are told the ratio of Dogs : Cats : Bunnies = 3 :7 : 11 also equal to 21

We are now told the total of 196 Dogs + Bunnies which means 3+11 =14 /21* X = 198
Solve for X to get the tota no of animals

= 2x = 588 or X = 294 animals

Dogs = 3/21* 294 = 42 ans choice A

My thoughts on how to solve this in under 1 minute.
D:C:B = 3:7:11
We have 196 = D + B.

Test answers. Start with B always: 66 dogs = 3 dogs * unknown multiplier. 66 / 3 = 22
22 is our unknown multiplier (for answer choice B).

Take that multiplier and apply it to the 11 bunnies: 22 * 11. We know 10 * 22 is already 220, but *STOP*. 10 * 22 = 220, but you only have 196 dogs AND bunnies, so you know the multiplier must be smaller. A is the only answer that is smaller.

Dogs: Bunnies => 3:11

Total = 196

Dogs = \(\frac{3 }{ (11+3)}\) * 196

=> \(\frac{ 3 }{14 }\) * 196

=> 42

Answer A

Since 3 + 11 = 14, we can say that, for every 14 dogs and bunnies, 3/14 are dogs and 11/14 are bunnies.
In other words, if there are n dogs and bunnies, then the number of dogs = 3/14 of n.

So for this question, the number of dogs = 3/14 of 196 = 42

Answer: A

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