The average temperature for Monday, Tuesday, Wednesday and Thursday was 48° . The average temperature for Tuesday, Wednesday, Thursday and Friday was 52°, If the temperature on Monday was 42°, then the temperature on Friday was (in degrees)

Options

A. 58
B. 56
C. 52
D. 50

Answer

To solve the problem step by step, we can follow these calculations:

### Step 1: Calculate the total temperature for Monday, Tuesday, Wednesday, and Thursday
Given that the average temperature for Monday, Tuesday, Wednesday, and Thursday is 48°, we can express this mathematically.

Let:
- M = Temperature on Monday
- T = Temperature on Tuesday
- W = Temperature on Wednesday
- R = Temperature on Thursday

The average is calculated as:
\[ \text{Average} = \frac{M + T + W + R}{4} \]
Substituting the given average:
\[ 48 = \frac{M + T + W + R}{4} \]
Multiplying both sides by 4 gives:
\[ M + T + W + R = 192 \quad \text{(Equation 1)} \]

### Step 2: Calculate the total temperature for Tuesday, Wednesday, Thursday, and Friday
Next, we know that the average temperature for Tuesday, Wednesday, Thursday, and Friday is 52°.

Let F = Temperature on Friday.

Using the same average formula:
\[ 52 = \frac{T + W + R + F}{4} \]
Multiplying both sides by 4 gives:
\[ T + W + R + F = 208 \quad \text{(Equation 2)} \]

### Step 3: Substitute the known temperature for Monday
We know that the temperature on Monday (M) is 42°.
Substituting M = 42 into Equation 1:
\[ 42 + T + W + R = 192 \]
This simplifies to:
\[ T + W + R = 192 - 42 \]
\[ T + W + R = 150 \quad \text{(Equation 3)} \]

### Step 4: Substitute Equation 3 into Equation 2
Now we can substitute Equation 3 into Equation 2:
\[ 150 + F = 208 \]
Solving for F gives:
\[ F = 208 - 150 \]
\[ F = 58 \]

### Conclusion
The temperature on Friday is **58°**.

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