A sweet seller has 420 kaju barfis and 130 badam barfis. She wants to stack them in such a way that each stack has the same number and they take up the least area of the tray. What is the maximum number of barfis that can be placed in each stack for this purpose?

Explanation

To solve the problem, we need to find the maximum number of barfis that can be placed in each stack such that both types of barfis are stacked evenly. This means we need to find the greatest common divisor (GCD) of the two quantities: 420 kaju barfis and 130 badam barfis.

### Step 1: Find the prime factorization of each number

1. **Prime factorization of 420:**
- Divide by 2: \( 420 \div 2 = 210 \)
- Divide by 2: \( 210 \div 2 = 105 \)
- Divide by 3: \( 105 \div 3 = 35 \)
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