When is the National Science Day observed

What value should come in place of the question mark (?) in the following question?

(13 X 11) + (19 X 3) = 400% of √?

What will come in place of (?) in the given expression.

{(60% of 250) + √144} ÷ (3² - 4) = ?

Find the result of

45 ÷ 3 of 6 of [12 ÷ 4 of (10 ÷ 2 + 1)] + (8 ÷ 2.5 + 1.8)

[{(3 × 54 × 21)/63} + 6] / 6 = √? 

((12+12+12+12)÷4)/((8+8+8+8+8+8)÷16) = ?

25% of 250 + 32% of 200 = ? ÷ √ 16

Evaluate: 96 ÷ 6 × (3 + 5) − 7²

119 ÷ [22 - {90 ÷ (23 - 105 ÷ (7 × 3))}] = ?

125 ÷ 5 + 14 × 4 = ? + 72 ÷ 4 – 35