Question 10 of 480
The sum of two numbers is twice their difference. If the difference of the numbers is P, find the larger of the two numbers
Correct Answer:
B
Explanation
To solve the problem, we need to analyze the relationship between the two numbers based on the information given. Let's denote the two numbers as \( x \) and \( y \), where we assume \( x \) is the larger number and \( y \) is the smaller number.
### Step 1: Set Up the Equations
1. **Sum of the Numbers**: The sum of the two numbers is given by:
\[
x + y
\]
2. **Difference of the Numbers**: The difference of the two numbers is given by:
\[
x - y
\]
3. **Given Condition**: According to the problem, the sum of the two numbers is twice their difference:
\[
x + y = 2(x - y)
\]
### Step 2: Simplify the Equation
Now, let's simplify the equation we derived from the given condition:
1. Start with:
\[
x + y = 2(x - y)
\]
2. Distribute the 2 on the right side:
\[
x + y = 2x - 2y
\]
3. Rearranging the equation to isolate terms involving \( x \) and \( y \):
\[
x + y + 2y = 2x
\]
\[
x + 3y = 2x
\]
4. Subtract \( x \) from both sides:
\[
3y = 2x - x
\]
\[
3y = x
\]
### Step 3: Express the Larger Number in Terms of P
We know from the problem that the difference of the numbers is \( P \):
\[
x - y = P
\]
Now, we can substitute \( x \) from the previous equation into this difference equation:
1. Substitute \( x = 3y \) into \( x - y = P \):
\[
3y - y = P
\]
\[
2y = P
\]
2. Solve for \( y \):
\[
y = \frac{P}{2}
\]
3. Now, substitute \( y \) back into the equation for \( x \):
\[
x = 3y = 3\left(\frac{P}{2}\right) = \frac{3P}{2}
\]
### Conclusion: Identify the Larger Number
From our calculations, we have found that the larger number \( x \) is:
\[
x = \frac{3P}{2}
\]
### Final Answer
Thus, the larger of the two numbers is:
**B. \( \frac{3P}{2} \)**
### Explanation of Other Options
- **Option A: \( \frac{P}{2} \)**: This represents the smaller number \( y \), not the larger number \( x \).
- **Option C: \( \frac{5P}{2} \)**: This value does not satisfy the conditions set by the problem and is not derived from our equations.
- **Option D: \( 3P \)**: This is also not derived from our equations and does not represent either number correctly.
### Revision Summary
- The sum of two numbers is twice their difference, leading to the equation \( x + y = 2(x - y) \).
- By expressing the larger number \( x \) in terms of the smaller number \( y \), we found \( x = 3y \).
- The difference \( P \) allowed us to express \( y \) as \( \frac{P}{2} \) and subsequently find \( x = \frac{3P}{2} \).
- The correct answer is \( \frac{3P}{2} \), which corresponds to option B.