RRB NTPC · प्रश्न 24
यदि 15 × 17 = 84, 92 × 23 = 57, 37 × 44 = 84, तो 54 × 32 = ?
उत्तर देखें और व्याख्या
उत्तर: (D) 51
व्याख्या
The first digit of the result is the sum of the second number's digits and the second digit is the difference of the first number's digits: 15 × 17 → (1+7)(5−1) = 84; 92 × 23 → (2+3)(9−2) = 57. So 54 × 32 → (3+2)(5−4) = 51.