Study the given pattern carefully and select the number from among the given options that can replace x.

In the first triangle the centre number is (top + bottom-left) ÷ 5 = (37 + 43) ÷ 5 = 16. Applying the same to the second: (47 + 53) ÷ 5 = 20. (The third triangle does not follow this neatly; the official RRB answer is 20.)