There are _____ students in a class and Average weight of class is 20 kg. When two new students include in the class average weight becomes 22 kg. After those four students left the class, whose weight half of the weight of two person included previously, then average weight of class becomes 25 kg.

The average age of 14 persons is 13 years. If the age of 15th persons is added, then the average remains same. What is the age (in years) of the 15th person?

Average age of a group of 16 boys is 24 years. Two boys with ages 19 years and 18 years left the group. One boy with age 43 years joined the group. What is the new average age (in years) of the group?

Average of 6 numbers is P. One number is removed. New average is P + 5. Which number was removed?

Average of 7 numbers is 28. One of these numbers is 22. 22 is replaced with a new number. New average becomes 30. What is that new number?

In a class, the average age of 28 boys is 13 years. Two boys whose ages are 'x' years and 21 years leave the class. If the new average age of the class is 13 years, then what is the value of 'x'?

A batsman has a certain average after 16 innings. In the 17 ^th inning, he scores 85 runs, thereby increasing his average by 3 runs. What is his new average ?

A set of fifteen numbers has an arithmetic mean of 42 . The mean of the first eight numbers is 39 , while the mean of the last eight numbers is 44 . The value of the eighth number is

The average age of Ram and Rohan is 45 years. If Aravind were to replace Ram, the average age would be 44 years; and if Aravind were to replace Rohan, the average age would be 46 years. What are the ages of Ram, Rohan and Aravind, respectively, in years?

The average of 10 observations is 40. It was realised later that an observation was misread as 31 in place of 50. Find the correct average.​

The average of 10 observations is 40. It was realised later that an observation was misread as 32 in place of 43. Find the correct average.​