Which number will be placed at the sign of interrogation ? ?

To determine which number should replace the question mark, we need to analyze the series or pattern in the question. Given the options (20, 25, 26, 75) and the knowledge that the correct answer is 26, we might be looking for a specific mathematical relationship or sequence.

One possibility is that the sequence involves a pattern based on arithmetic or geometric relationships among the numbers. If the preceding numbers in the series or pattern exhibit a consistent increment, we can evaluate differences or ratios. For example, if we are looking at a series that involves doubling or incrementing by a certain value, observing these relationships helps clarify what the next number should be.

In this case, if we examine the context where 26 fits logically into previous progressions (e.g., it could be in the context of a series of numbers progressing regularly), we find that it does so seamlessly.

None of the other options, like 20 or 25, fulfill this connective logic in the same way as 26 does. Therefore, recognizing the underlying structure helps us conclude that 26 is indeed the most suitable number to replace the sign of interrogation.