Approximations

(575.98/?)×13.98 + 35.89% of 450.09 = 15.11% of 2199.97
(576/?)×14 + 36% of 450 = 15% of 2200
(576/?)×14 + (36/100)×450 = (15/100)×2200
(576/?)×14 + 162 = 330
(576/?)×14 = 330 - 162
? = (576×14)/168
? = 48.

∛(14.98 % of 750 - 34 × 4.03 = ?^(1/3)) - 33
⇒ ∛(15 % of 750 - 34 × 4 = ?^(1/3)) - 33
⇒ 112.5 - 34 × 4 + 33 = ?^(1/3)
⇒ 113 - 136 + 33 = ?^(1/3)
⇒ ?^(1/3) = 10
⇒ ? = 1000
Hence, option D is correct.

105.1% of 8401.01 - $$\frac{3}{7}$$% of 5600.12 + 9.999 = ?
105% of 8400 - $$\frac{3}{7}$$% of 5600 + 10 = ?
(105/100)×8400 - ($$\frac{3}{7}$$00)×5600 + 10 = ?
8820 - 24 + 10 = ?
? = 8806.

( √14.03 + √27.99)² + 141.07 - 2 √392 = ?² -106
⇒ (√14 + √28)² + 141 - 2 √392 = ?² - 106
⇒ or, (√14)² + (√28)² + 2 ×√( 14 × 28) + 141 - 2 √392 = ?² - 106
⇒ or, 14 + 28 + 2 √392 + 141 - 2 √392 = ?
⇒ or, 14 + 28 + 141 = ?² - 106
⇒ or, 183 = ?² - 106
⇒ or, ?² = 183 + 106
⇒ or, ?² = 289
⇒ ? = 17
Hence, option C is correct.

2831.994 ÷ 23.998 + 11.99² ÷ 5.991 = ?²
⇒ 2832/24 + 12²/6 = ?²
⇒ 118 + 144/6 = ?²
⇒ 118 + 24 = ?²
⇒ 142 = ?²
⇒ √142 = ?
⇒ ? ≅ √144
⇒ ? ≅ 12

Given expression, 3456.87 ÷ 99.87 + 4345 ÷ 100.12 = 4/5 of ?
⇒ 4/5 of ? ≅ 3457/100 + 4345/100
⇒ 4/5 of ? ≅ 34.57 + 43.45
⇒ 4/5 of ? ≅ 78.02
⇒ ? ≅ 78.02 × (5/4)
⇒ ? ≅ 390.1/4
⇒ ? ≅ 97.525
⇒ ? ≅ 98

Given expression:
[(14.84% of 379.97) + (35.35% of 420.02) - ($$\frac{2}{5}$$) × 575.2 + 9.8% of 2300.6] / √(9.87 - 5.78)
≅ [(15% of 380) + (35% of 420) - ($$\frac{2}{5}$$) × 575 + 10% of 2300] / √(10 - 6)
≅ [57 + 147 - 230 + 230] / √(4)
≅ [57 + 147] / 2
≅ [204] / 2
≅ 102

1555 - 24.8% of 858 + 960 of (11/15.9)= ?
Approximates value can be calculated as
⇒ 1555 - 25% of 860 + 960 of (11/16)
⇒ 1555- 215 + 660 = 2000
Hence, the answer is : 2000

21 + 67 ÷ 17 - 9.98% of 59.91= ? - 59.88% of 85.10
Approximates value can be calculated as
⇒ 21 + 4 - 10% of 60 = ? - 60% of 85
⇒ 21 + 4 -6 + 51 = 70
Hence, the answer is : 70