If 1 2 = 3, 2 3 = 8, 3 4 = 15, then 4 5 = ?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 24.
1 × 2 → (1 × 2) + 1 = 2 + 1 = 3
2 × 3 → (2 × 3) + 2 = 6 + 2 = 8
3 × 4 → (3 × 4) + 3 = 12 + 3 = 15
4 × 5 → (4 × 5) + 4 = 20 + 4 = 24