List of top General Questions on Average asked in CUET (PG)

Two trains cross each other in \(15\) seconds when they are approaching each other from opposite directions whereas they cross each other in \(45\) seconds when they are moving in same direction. Calculate their possible speeds.
The average age of a group of boys and girls is 18 years. If the average age of boys is 20 years and that of girls is 15 years, then what is the percentage of boys in the group?