The average temperature from Monday, Tuesday, Wednesday is `38^(@)C` . While the average temperature Tuesday, Wednesday, Thursday is `43^(@)C` . If the average temperature of Monday and Thursday is `18.5^(@)` CFind the temperature of Monday.

Answer

To find the temperature of Monday, we can follow these steps:

### Step 1: Calculate the Total Temperature for Monday, Tuesday, and Wednesday
Given that the average temperature from Monday, Tuesday, and Wednesday is \(38^\circ C\), we can calculate the total temperature for these three days.

\[ \text{Total Temperature (Monday + Tuesday + Wednesday)} = \text{Average} \times \text{Number of Days} = 38 \times 3 = 114^\circ C \]

### Step 2: Calculate the Total Temperature for Tuesday, Wednesday, and Thursday
Next, we know that the average temperature from Tuesday, Wednesday, and Thursday is \(43^\circ C\). We can calculate the total temperature for these three days.

\[ \text{Total Temperature (Tuesday + Wednesday + Thursday)} = 43 \times 3 = 129^\circ C \]

### Step 3: Calculate the Total Temperature for Monday and Thursday
We are also given that the average temperature of Monday and Thursday is \(18.5^\circ C\). We can calculate the total temperature for these two days.

\[ \text{Total Temperature (Monday + Thursday)} = 18.5 \times 2 = 37^\circ C \]

### Step 4: Set Up the Equations
Now we have three equations based on the totals calculated:

1. \( M + T + W = 114 \) (Equation 1)
2. \( T + W + Th = 129 \) (Equation 2)
3. \( M + Th = 37 \) (Equation 3)

Where:
- \( M \) = Temperature on Monday
- \( T \) = Temperature on Tuesday
- \( W \) = Temperature on Wednesday
- \( Th \) = Temperature on Thursday

### Step 5: Express \( Th \) in Terms of \( M \)
From Equation 3, we can express \( Th \):

\[ Th = 37 - M \]

### Step 6: Substitute \( Th \) into Equation 2
Substituting \( Th \) into Equation 2 gives us:

\[ T + W + (37 - M) = 129 \]

This simplifies to:

\[ T + W - M = 129 - 37 \]
\[ T + W - M = 92 \quad \text{(Equation 4)} \]

### Step 7: Substitute \( T + W \) from Equation 1
From Equation 1, we know:

\[ T + W = 114 - M \]

Substituting this into Equation 4 gives:

\[ (114 - M) - M = 92 \]
\[ 114 - 2M = 92 \]

### Step 8: Solve for \( M \)
Now, we can solve for \( M \):

\[ 114 - 92 = 2M \]
\[ 22 = 2M \]
\[ M = \frac{22}{2} = 11^\circ C \]

### Conclusion
The temperature of Monday is \( 11^\circ C \).

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