In an exam, the average marks obtained by the students was found to be 60. After omission of computational errors, the average marks of 100 candidates had to be changed from 60 to 30 and the average with respect to all the examinees came down to 45 marks. The total number of candidates who took the exam, was. 

The average of 12 number is 42. If a 13th number is added, then the average becomes 44. What is the 13th number?

The average of 10 numbers is calculated as 15. It is discovered later on that while calculating the average one number, namely 36, was wrongly read as 26. The correct average is: 

There are 100 students in 3 sections A, B and C of a class. The average marks of all the 3 sections was 84. The average of B and C was 87.5 and the average marks of A is 70. The number of students in A was. 

The average of 24 number is 65. The average of first 11 number is 67 and the average of last 10 number is 70. If the 12^th Number is 13 less than the 13^th number , and the 14^th number is  one more than the 13^th number, then the average of 12^th and 14^th number is:

The average weight of 29 students is 40 kg. If the weight of teacher be included the average weight increased by 400 gms. The weight of the teacher is-

The average age of 24 boys and their teacher is 15 years. When the teacher's age is excluded, the average age decreases by 1 year. The age of the teacher is: