The chief source of naphthalene

Find the approximate value of Question mark(?) for given equation. 

(47.98 × 34.85 ÷ 7.09) – (80.81 ÷ 9.02 × 5.01) = ?

Find the ratio of the area of an equilateral triangle of side ‘a’ cm to the area of a square having each side equal to ‘a’ cm.

(14.98% of 319.99) - 7.998 = √?

(699.88% of 32) + (80.44% of 400.23) = ? + (11.67)²

12.02³ + 32.05 × 16.08 – 84.04% of 2400 = 56.06% of ?

1587.9 + 9650.98 + 10612.8 =?³ - 2536.67

(?)² + 9.11³ = 31.9² – 39.03 

(1550.23 ÷ 30.98) + (864.32 ÷ 23.9) + 1724.11 = ?

(10.98% of 499.99) - 4.998 = √?