Monika and Vasu have the same weight, if they both gain weight by 2kg, how will their new weight be compared?
(a) What mathematical concept has been converted in this question?

Answer

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

### Step 1: Define the weights
Let the weight of Monika be represented as \( mw \) and the weight of Vasu as \( mv \).

### Step 2: Establish the equality of weights
According to the problem, Monika and Vasu have the same weight. Therefore, we can write:
\[ mw = mv \]

### Step 3: Add the weight gain
Both Monika and Vasu gain 2 kg. We can express their new weights as follows:
- New weight of Monika: \( mw + 2 \)
- New weight of Vasu: \( mv + 2 \)

### Step 4: Write the new weights in terms of the original weights
Since we established that \( mw = mv \), we can substitute \( mv \) for \( mw \) in the new weight expressions:
- New weight of Monika: \( mw + 2 \)
- New weight of Vasu: \( mw + 2 \) (since \( mv = mw \))

### Step 5: Compare the new weights
Now, we can compare the new weights:
\[ mw + 2 = mv + 2 \]

### Conclusion
Since both new weights are equal, we conclude that:
- The new weight of Monika is equal to the new weight of Vasu.

### Answer to the second part of the question
The mathematical concept used in this question is **Euclid's second axiom**, which states that if equals are added to equals, the results will be equal.

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