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

3/4 of 26% of 850 = ?

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

672 ÷ 24 X 18 + 153 - 345 = ?

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

√1521 ÷ 3 X 12 = ?

In the question given below which one of the five answer figures on the right should come after the problem figures on the left, if the sequence were continued?

In the question given below which one of the five answer figures on the right should come after the problem figures on the left, if the sequence were continued?

In the question given below which one of the five answer figures on the right should come after the problem figures on the left, if the sequence were continued?