List of top Quantitative Aptitude Questions on Average

There are three persons A B, and C in a room. If a person D joins the room, the average weight of the persons in the room reduces by x kg . Instead of D , if person E joins the room, the average weight of the persons in the room increases by 2 kg x . If the weight of E is 12 kg more than that of D , then the value of x is

The total age of a group of 20 children is 160 years. If the average age of 8 of the children of the group is 12 years, find the average age of the remaining group.

A person brought a load of bags towards a weighing machine and measured the weights of the bags in a particular order. First, he weighed three bags individually, then weighed the bags taking two at a time of different combinations and lastly weighed all the three bags at a time. The recorded weight for the last measure was 203 kg. What is the average of the 7 measurers he has taken?