Question 214 of 480
If the operation * on the set of integers is defined by P * Q = \(\sqrt{PQ}\), find the value of 4 * ( 8 * 32).
Correct Answer:
A
Explanation
To solve the problem, we need to evaluate the expression \(4 * (8 * 32)\) using the operation defined as \(P * Q = \sqrt{PQ}\). Let's break this down step-by-step.
### Step 1: Evaluate the inner operation \(8 * 32\)
According to the operation defined, we have:
\[
8 * 32 = \sqrt{8 \cdot 32}
\]
Now, we need to calculate \(8 \cdot 32\):
\[
8 \cdot 32 = 256
\]
Next, we take the square root of 256:
\[
\sqrt{256} = 16
\]
So, we find that:
\[
8 * 32 = 16
\]
### Step 2: Substitute back into the original expression
Now that we have evaluated \(8 * 32\), we can substitute this value back into the original expression:
\[
4 * (8 * 32) = 4 * 16
\]
### Step 3: Evaluate the operation \(4 * 16\)
Using the same operation definition, we calculate:
\[
4 * 16 = \sqrt{4 \cdot 16}
\]
Now, we calculate \(4 \cdot 16\):
\[
4 \cdot 16 = 64
\]
Next, we take the square root of 64:
\[
\sqrt{64} = 8
\]
### Final Answer
Thus, the value of \(4 * (8 * 32)\) is:
\[
\boxed{8}
\]
### Explanation of Other Options
Now, let's analyze the other options to understand why they are incorrect:
- **Option B: 3** - This value does not relate to any calculations we performed. The operations we executed led us to 8, and there is no mathematical basis for arriving at 3 in this context.
- **Option C: 16** - This option might seem plausible because we calculated \(8 * 32\) to be 16. However, we need to remember that we are looking for \(4 * (8 * 32)\), which we found to be 8, not 16.
- **Option D: 4** - This option is also incorrect. While 4 is a number involved in our calculations, it does not represent the final result of the operation we performed.
### Summary of Key Points
- The operation defined is \(P * Q = \sqrt{PQ}\).
- We first evaluated \(8 * 32\) to get 16.
- We then evaluated \(4 * 16\) to get 8.
- The correct answer is \(8\), which corresponds to option A.
### Revision Summary
- Understand the operation defined: \(P * Q = \sqrt{PQ}\).
- Break down complex expressions into simpler parts.
- Always substitute back the results into the original expression.
- Double-check calculations to avoid common pitfalls, such as misinterpreting the order of operations.