In such type of questions, clues are given regarding comparisons among a set of persons or things with respect to one or more qualities. The candidate is required to analyse the whole information, form a proper ascending / descending sequence and then answer the given questions accordingly.
A * B means A and B are of the same age;
A - B means B is younger than A;
A + B means A is younger than B;
X + Y + Z is same aste
X + Y + Z means X is younger than Y and Y is younger than Z. This can also be written as Z - Y - X.