Simple Average — Prelims Questions

The average of 5 consecutive odd numbers is 21. What is the sum of the largest and smallest of these numbers?

In a class of 30 students, the average marks in Mathematics is 75. If 5 students who scored an average of 90 marks leave the class, what will be the new average of the remaining students?

The average of first 20 natural numbers is A, and the average of first 20 even natural numbers is B. What is the value of B - A?

A batsman's average after 10 innings is 32 runs. In the 11th innings, he needs to score at least how many runs to have an average of 34 runs?

If the average of 7 consecutive integers is 15, what is the average of the squares of these integers?