$${\sqrt{4×?}}={160\over 10}$$

Direction: What approximate value will come in place of the question mark (?) in the following question? (You are not expected to calculate the exact value)

(16.05)² + (8.96)² - 7.03 × 3.98 =? + 197.99

$$ {40 \%}\ of( {20\over 4}×?)=48$$

What should come in place of the question mark (?) in the following mathematical statement?
$${{?^6÷16=108}}$$

Evaluate the following:
5 - [96 ÷ 4 of 3 - (16 - 55 ÷ 5)]

If 5x + 5 > 2 + 2x and 5x + 3 ≤ 4x + 5; then x can take which of the following values?

$$ {4\over 7}×{2{4\over 5}} ÷{2\over 5}=?$$

 If $${1\over 4.263}=0.2346$$, find the value of $${1\over0.0004263}.$$