Averages Questions with Solutions

15 questions11 easy3 medium1 hard

An average is the sum of a set of values divided by the number of values. Average questions in entrance exams go well beyond this basic formula: they test what happens when a person joins or leaves a group, when a wrong value is corrected, the average age of a family over time, weighted averages of two groups, and averages of consecutive numbers. The fastest approach is the deviation method. Instead of adding every value, assume an average, note how far each value is above or below it, and adjust. For example, if a new member raises a group's average by 2, the new member is 2 times the new group size above the old average. Questions on cricket scores and batting averages are a common variation. Practise the average questions below, each with a full solution and a shortcut using the deviation method where it applies.

  1. Q1.

    A set of consecutive positive integers beginning with 1 is written on the blackboard. A student came along and erased one number. The average of the remaining numbers is . What was the number erased?

    A. 7B. 8C. 9D. None of the above
    hardAsked in NIMCET 2020View solution ›