Multiple choice

What approximate value should come in place of question mark (?) in the following question? $159 \times 43 - 37 \times 57 = ?^2$

  1. 40

  2. 50

  3. 60

  4. 70

  5. 80
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Calculate 159 × 43 = 6837 and 37 × 57 = 2109. Difference = 6837 - 2109 = 4728. We need ?² = 4728, so ? = √4728 ≈ 68.76. Among options, 70 (Option D) is closest since 70² = 4900 and 68² = 4624; 4728 is nearer to 4900.

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