A batsman scored 87 runs in the 21st match in his career. His average of runs per match increased by 2. What was his average before the 21st match?

The heights of six people are given as 6 feet 6 inches, 6 feet, 5 feet 8 inches, 6 feet 2 inches, 6 feet 4 inches, and 5 feet 10 inches, respectively. Find the average height of these six people.

Total weekly emoluments of the workers of a factory is 1534. Average weekly emolument of a worker is 118. The number of workers in the factory is:

The number of students in section A and section B of a class are 40 and 52, respectively. The average score in mathematics of all the students is 75. If the average score of the students in A is 20% more than that of students in B. then what is the average score of students is B?

A man bought 13 articles at 70 each, 15 at 60 each and 12 at 65 each. The average price per article is 

The average score in Mathematics of 90 students of section A and B of class IX was 63. The number of students in A were 10 more than those in B. The average score of students in A was 30% more than that of students in B. The average score of students in B is:

If the average marks of three batches of 30, 50 and 70 students is 55, 70 and 70 respectively, then the average marks of all the students is:

The average score of 14 students was calculated as 71. But later it was found that marks of one student were recorded as 42 instead of 56 and as 74 instead of 32 of the other. Correct average?