What will come in place of the question mark (?) in the following questions?

? % of 625 + 20% of 955 = (21) ²

If 3ˣ × 9¹⁵ × 27⁶ = 81¹⁶, then the value of x is:

Value of$$\frac{0.97 \times 0.97 \times 0.97 + 0.03 \times 0.03 \times 0.03}{0.97 \times 1.94 - 1.94 \times 0.03 + 0.03 \times 0.06}$$​ is equal to:

The value of $$\frac{(0.\overline{29} \div 0.\overline{32}) \times 6.6}{0.\overline{95} \div 1.\overline{05} \times 1.\overline{2}}$$​ is

Simplify the following.
$$3\left(\left(\frac{7}{3}\right)x^{2} - 25x + 12\right) - 7\left(x^{2} + 8x - 16\right)$$​

What digit would come in the place of * in the following multiplication?

(427) × (2*6) = 126392

$$4\frac{1}{10}-\left[2\frac{1}{2}-\left\{\frac{5}{6}-\left(\frac{2}{5}+\frac{3}{10}-\frac{4}{15}\right)\right\}\right]$$​on simplification gives

Evaluate:
16 + 8 ÷ 4 − 3 × 4

Evaluate:
(−9) − (−60) ÷ (−12) + (−4) × 8

Evaluate: (-9) - (-60) ÷ (-12) + (-4) × 7

The value of 66 - 2 × [ 10 + 2 × { 18 - 2 ( 7 - 4 ) × 3} ÷ 50] is: