Find Number of Dogs

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In summary: Yes, that was a typo, thank you for catching it. And yes, you got the right answer, great job! Keep up the good work.
  • #1
nycmathdad
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A certain pet store sells only dogs and cats. In March, the store sold twice as many dogs as cats. In April, the store sold twice the number of dogs that it sold in March, and three times the number of cats that it sold in March. If the total number of pets the store sold in March and April combined was 500, how many dogs did the store sell in March?

Let me see.

Note: twice as many dogs as cats in March:

Dogs = 2x

Cats = x

In April:

Dogs = 2(2x) + 3x

Total number of pets sold = 500

Here is my equation:

2x + x + 2(2x) + 3x = 500

10x = 500

x = 500/10

x = 50

In March, the store sold twice as many dogs as cats. Here, x represents the number of cats. Twice that amount is 100. I say the number of dogs sold in March is 100.

You say?
 
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  • #2
Beer soaked ramblings follow.
nycmathdad said:
...
You say?
I say you should be done with mind numbing trivial stuff like this after 14 years of Precalculus review. You should be doing something more challenging.
 
  • #3
nycmathdad said:
A certain pet store sells only dogs and cats. In March, the store sold twice as many dogs as cats. In April, the store sold twice the number of dogs that it sold in March, and three times the number of cats that it sold in March. If the total number of pets the store sold in March and April combined was 500, how many dogs did the store sell in March?

Let me see.

Note: twice as many dogs as cats in March:

Dogs = 2x

Cats = x

In April:

Dogs = 2(2x) + 3x
No. The number of dogs sold was 2(2x)= 5x and the number of cats sold was 3x.
The total number of pets sold in April was 2(2x)+ 3x= 7x.

Total number of pets sold = 500

Here is my equation:

2x + x + 2(2x) + 3x = 500

10x = 500

x = 500/10

x = 50

In March, the store sold twice as many dogs as cats. Here, x represents the number of cats. Twice that amount is 100. I say the number of dogs sold in March is 100.

You say?
Yes, that is correct. It would be a good idea to check your work in the words of the original problem:1
"A certain pet store sells only dogs and cats. In March, the store sold twice as many dogs as cats.
If the store sold 50 cats and 100 dogs in March then, yes, the store sold twice as many dogs as cats.

"In April, the store sold twice the number of dogs that it sold in March,"
So in April the store solve 2(100)= 200 dogs.

"and three times the number of cats that it sold in March."
So the store sold 3(50)= 150 cats in March

"If the total number of pets the store sold in March and April combined was 500"
50+ 100+ 200+ 150=300+ 200= 500. Yes, that checks.

It was intelligent of you to write 2x= 100 dogs as the answer. A lot of people would have arrived at "x= 50" and stopped there!
 
  • #4
Country Boy said:
No. The number of dogs sold was 2(2x)= 5x and the number of cats sold was 3x.
The total number of pets sold in April was 2(2x)+ 3x= 7x.Yes, that is correct. It would be a good idea to check your work in the words of the original problem:1
"A certain pet store sells only dogs and cats. In March, the store sold twice as many dogs as cats.
If the store sold 50 cats and 100 dogs in March then, yes, the store sold twice as many dogs as cats.

"In April, the store sold twice the number of dogs that it sold in March,"
So in April the store solve 2(100)= 200 dogs.

"and three times the number of cats that it sold in March."
So the store sold 3(50)= 150 cats in March

"If the total number of pets the store sold in March and April combined was 500"
50+ 100+ 200+ 150=300+ 200= 500. Yes, that checks.

It was intelligent of you to write 2x= 100 dogs as the answer. A lot of people would have arrived at "x= 50" and stopped there!
In your reply, you said 2(2x) = 5x. I assume this to be a typo. I got the right answer. Another check for me.
 

1. How do you determine the number of dogs in a given area?

To determine the number of dogs in a given area, you can conduct a survey or census by going door-to-door and asking residents if they own a dog. Another method is to use satellite imagery to count the number of dog houses or dog parks in the area. You can also contact local animal shelters or veterinarians for data on the number of registered dogs in the area.

2. Can you accurately estimate the number of stray dogs in a city?

It is difficult to accurately estimate the number of stray dogs in a city due to their transient nature and the lack of a central database. However, you can use statistical methods such as sampling and extrapolation to estimate the number of stray dogs in a given area.

3. How does the number of dogs in a household affect their behavior?

The number of dogs in a household can have an impact on their behavior. Dogs in larger households may have more opportunities for socialization and play, while dogs in smaller households may have more one-on-one attention from their owners. However, every dog is unique and their behavior is influenced by a variety of factors, not just the number of dogs in their household.

4. Are there any ethical concerns with counting the number of dogs?

There may be ethical concerns with counting the number of dogs, especially if it involves entering private property or collecting personal information from owners. It is important to obtain consent and follow ethical guidelines when conducting research on animals.

5. How can knowing the number of dogs in an area be useful?

Knowing the number of dogs in an area can be useful for various reasons. It can help with planning and implementing animal control measures, such as vaccination and spaying/neutering programs. It can also provide valuable data for research on dog behavior and population dynamics. Additionally, it can assist in identifying areas with a high concentration of dogs, which may require more resources for pet care and services.

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