The average temperature of Delhi for Monday, Tuesday and Wednesday was `25^@C`, while for Thursday, Wednesday and Tuesday, it was `26^@C`. If the temperature on Thursday was `27^@C`, them what was the temperature on Monday?

Options

A. `21^@C`
B. `24^@C`
C. `27^@C`
D. `30^@C`

Answer

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

### Step 1: Set up the equations based on the given averages.

1. **Average temperature for Monday, Tuesday, and Wednesday**:
\[ \frac{M + T + W}{3} = 25 \]
Multiplying both sides by 3 gives:
\[ M + T + W = 75 \quad \text{(Equation 1)} \]

2. **Average temperature for Thursday, Wednesday, and Tuesday**:
\[ \frac{Th + W + T}{3} = 26 \]
Multiplying both sides by 3 gives:
\[ Th + W + T = 78 \quad \text{(Equation 2)} \]
We know that the temperature on Thursday (Th) is 27°C, so substituting that in gives:
\[ 27 + W + T = 78 \]
Rearranging this gives:
\[ W + T = 78 - 27 = 51 \quad \text{(Equation 3)} \]

### Step 2: Substitute Equation 3 into Equation 1.

From Equation 1:
\[ M + T + W = 75 \]
Substituting \(W + T\) from Equation 3:
\[ M + 51 = 75 \]

### Step 3: Solve for M (Monday's temperature).

Subtract 51 from both sides:
\[ M = 75 - 51 \]
\[ M = 24 \]

### Conclusion:
The temperature on Monday is **24°C**.

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