Q72. 20.99² − 24.97% of 220.02 − ? = 131.13

Question

Q72. 20.99² − 24.97% of 220.02 − ? = 131.13

1. A. 225
2. B. 125
3. C. 255 (Correct answer)
4. D. 145
5. E. 290

Correct Answer

Option C — 255

Detailed Solution & Explanation

The correct answer is 255.

Key Points

• Approximate each term and solve for the missing number (?).
• 20.99² ≈ 21² = 441.
• 24.97% of 220.02 ≈ 25% of 220 = 55.
• So the equation becomes 441 − 55 − ? = 131.13 ≈ 131.
• 441 − 55 = 386, hence ? = 386 − 131 = 255.
• simplify left to right after rounding — square the near-integer (21² = 441), take the easy percentage (25% = one quarter), then isolate the unknown by subtraction.

Exam Tip

• 25% of any number is just that number ÷ 4 (220 ÷ 4 = 55) — recognising 'nice' percentages (25%, 50%, 20%, 10%) as simple fractions makes approximation sets very fast.