Question
A pet shop has a total of 21 dogs and birds. Altogether there are 56 feet. How many dogs are there and how many birds? A. 6 dogs and 15 birds B. 7 dogs and 14 birds C. 9 dogs and 12 birds D. 8 dogs and 13 birds
Ask by Huff Tyler. in the United States
Mar 09,2025
Upstudy AI Solution
Tutor-Verified Answer
Answer
There are 7 dogs and 14 birds.
Solution
Let \( d \) be the number of dogs and \( b \) be the number of birds. We are given:
1. Total animals:
\[
d + b = 21
\]
2. Total feet (dogs have \( 4 \) feet and birds have \( 2 \) feet):
\[
4d + 2b = 56
\]
**Step 1: Express \( b \) in terms of \( d \) from the first equation.**
\[
b = 21 - d
\]
**Step 2: Substitute \( b = 21 - d \) into the second equation.**
\[
4d + 2(21 - d) = 56
\]
**Step 3: Simplify and solve for \( d \).**
\[
4d + 42 - 2d = 56
\]
\[
2d + 42 = 56
\]
\[
2d = 56 - 42
\]
\[
2d = 14
\]
\[
d = 7
\]
**Step 4: Find \( b \) using the value of \( d \).**
\[
b = 21 - 7 = 14
\]
Thus, there are \( 7 \) dogs and \( 14 \) birds.
The correct answer is **B. 7 dogs and 14 birds**.
Answered by UpStudy AI and reviewed by a Professional Tutor
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Simplify this solution Bonus Knowledge
Let's break it down! Since each dog has 4 feet and each bird has 2, we can set up equations based on the total number of animals and feet. If we denote the number of dogs as \( d \) and birds as \( b \), we have: 1. \( d + b = 21 \) (total number of animals) 2. \( 4d + 2b = 56 \) (total number of feet) By substituting \( b = 21 - d \) into the second equation, we can solve for \( d \). After simplifying, we find that the solution leads us to \( d = 7 \) and \( b = 14 \). Thus, the answer is B: 7 dogs and 14 birds! And just a fun fact: Did you know that the average dog has about 3 to 5 different types of barks? They sure know how to communicate in style!
