Multiple choice

What approximate value should come at place of question mark (?) in the following question? $79\% of 488 - 129\% of 248 = ?^2 - 10.2^2$

  1. 5

  2. 8

  3. 13

  4. 11

  5. 17

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Calculate 79% of 488 ≈ 386, and 129% of 248 ≈ 320. So LHS ≈ 386 - 320 = 66. The equation becomes 66 = ?² - 10.2², which means 66 = ?² - 104, so ?² = 170, and ? ≈ 13. Answer C (13) is correct.