Average Questions

The average of 100 items was found to be 30 . If at the time of calculation , two items were wrongly taken as 32 and 12 instead of 23 and 11 , then the correct average is

The average marks obtained by a group of 16 students was 20. One student left the group as a result of which the average of the remaining students rose to 21. But another student joined, as a result of which the average marks of the group dropped a bit and became 20.5. What was the average marks obtained by the student who left and the one who joined?

The mean of marks secured by 65 students in division A of class X is 54, 30 students of division B is 50 and that of 55 students of division C is 48. Find the mean of marks of the students of three divisions of Class X.

The average height of 30 boys out of a class of 50 is 160 cm. If the average height of the remaining boys is 165 cm, the average height of the whole class (in cm) is:

The mean of 100 observations was calculated as 40. It was found later on that one of the observations was misread as 83 instead of 53. The correct mean is:

What is the average of all the one digit and two digit natural numbers?

What is the average of all numbers between 100 and 200 which are divisible by 13?

The average of four consecutive odd numbers is 64. What is the value of largest number?