Number Systems

The given numbers: 21, 38, 55, 106 satisfy: Using cross multiplication: Expanding: Cancel : Rearrange:
Thus, the correct answer is 4.

- The number is 3124698. - The digit 2 is in the ten-thousands place. Step 1: Calculate the Face Value: Step 2: Calculate the Place Value: Step 3: Compute the difference:
Thus, the correct answer is 19998.

Let’s take the number 473.
- Adding 1 to the second digit (7) gives 8.
- Subtracting 1 from the third digit (3) gives 2.
- Now, swapping the first and third digits, we get 274.

Similarly, applying the same transformation to other numbers:
- 568 becomes 685.
- 382 becomes 283.
- 847 becomes 478.

Thus, 274 is the smallest number, corresponding to the original number 473.