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

2345 + 4235 - 4634 = ? – 1000

If 30% of 50% of 4/7 of a number is 303, find the number.

1/30 is what percentage of 1/90 ?

1/30 is what percentage of 1/80 (rounded off to two decimal places)?

A milk vendor sold 25 / 200 ml, 15 / 500 ml and 9 / 750 ml of milk in three successive days. How many litres of milk did she sell in all three days ?

If 20% of a number is added to 84, then the result is the same number. 75% of the same number is:

$$\frac 1{20}$$​ is what percentage of $$\frac {10}{60}$$​?

Find the value of m, satisfying the equation:
$$\left(\frac{23}{2}\right)^3 \times \left(\frac{2}{23}\right)^{14} \times \left(\frac{23}{2}\right)^5=\left(\frac{2}{23}\right)^{6m+9}$$​

Simplify: (24 - 6 × 3) + 18 ÷ 3 × 2

​$$\frac{1}{20}$$​ is what percentage of $$\frac{2}{70}$$​?

If 60% of 30% of $$\frac13$$​ of a number is 204, find the number.