Question

3-Read Activity

There once lived two very sweet and very energetic dogs. Rexy was a small red dog that weighed 8 pounds. Bibi was an old gray dog. She weighed 10 1/2 pounds. These two dogs ate a lot of food. Every week their owner had to buy them 12 pounds of dog food.

1. What is this situation about?


2. What are the quantities in this situation?


3. What mathematical questions could we ask?


4. Answer one of your questions!

Answer 1

Bibi ate 6.3 pounds of food, approximately.

Rexy ate 5.7 pounds of food, approximately.

Explanation:

1. What is this situation about?

The situation described is about the amount of food those dogs eat, and its relation with their weights.

2. What are the quantities in this situation?

The quantities are aboth the weight of each dog, and the number of pounds of dog food.

3. What mathematical questions could we ask?

We could ask the pounds of food each dog eats, in proportion with their weights.

4. Answer the question.

To answer that question, we just need to form a proportion.

`(8)/(10.5)=(12-x)/(x)`

Where
`12-x` is the total pounts Rexy ate, and
`x` is the total pounts Bibi ate.

`8x=126-10.5x\\8x+10.5x=116\\18.5x=116\\x=(116)/(18.5) \approx 6.3`

Therefore, Bibi ate 6.3 pounds of food, approximately.

Then,
`12-x = 12-6.3 = 5.7`

Which means, Rexy ate 5.7 pounds of food, approximately.