If 9 × 7 = 3545 and 4 × 3 = 1520 then 6 × 8 = ?
2025
If 9 × 7 = 3545 and 4 × 3 = 1520 then 6 × 8 = ?
- A.
5040
- B.
6050
- C.
4030
- D.
3040
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Show answer & explanation
Correct answer: C
Key insight: form two two-digit blocks by multiplying the second number by 5 and then the first number by 5, and concatenate those blocks.
Step 1: Multiply the second number by 5. For 6 × 8, 8 × 5 = 40.
Step 2: Multiply the first number by 5. For 6 × 8, 6 × 5 = 30.
Step 3: Concatenate the two results with the second-number block first, then the first-number block: 40 and 30 → 4030.
Answer: 4030