Explanation:

Question – Are there more than 100 figures in that book?

Using S1 alone, number of figures on any page could be 0, 1 or 2. So minimum 0 (if every page will contain 0 figures) and maximum 102 figures (if every page will contain 2 figures) are possible. So S1 is not sufficient to answer the question uniquely.

Using S2 alone, number of figures on any single page could 1, 2, 3, … up to infinity. So it is also not sufficient to answer the question alone.

Even combining both we can have either 1 or 2 figures on any page. Which gives us minimum 51 (if every page will contain 1 figure) and maximum 102 figure (if every page will contain 2 figures). So it can’t be answered uniquely even by combining S1 and S2.