Solve the following exercise:
21+21=?
To solve this problem, we need to add the two fractions 21+21. Since the fractions have the same denominator, we apply fraction addition rules by:
- Add the numerators: 1+1=2.
- Keep the denominator the same: 2.
- The resulting fraction is 22.
- Simplify 22 to 1 since the numerator and denominator are equal.
Therefore, the sum of 21+21 is 1.
The correct answer is option 3: 1.