Age class 1 by gagan sir 

1.Problems on Ages - Concept and Basics
2.Tips and Tricks to Solve Problems on Ages
3.Important Formulas
4.Sample Questions - Problems on Ages
The problems based on age asked in the quantitative aptitude section are kind of brain teasers which when read at first may seem to be complex, but when solved step by step is easy to answer.
Questions from this section mostly are asked for 2-3 marks but there are chances of age-based questions being asked as a part of the data sufficiency or data interpretation. So it is important that the concept is clear to each and every candidate.
As the name suggests, the questions are word problems based on the ages of the people. They may be asked in equation form or direct form.