2
The average weight of a group of seven boys in 56kg. The individual weights (in kg) of six of them are 52, 57, 55, 60, 59 and 55. Find the weight of the seventh boy.
4
A student was asked to find the arithmetic mean of the following 12 numbers: 3, 11, 7, 9, 15, 13, 8, 19, 17, 21, 14 and `x`. He found the mean to be 12. The value of `x` will be:
5
The average of 100 observations was calculated as 35. It was found later, that one of the observations was misread as 83 instead of 53. The correct average is:
6
If the average weight of 6 students is 50 kg; that of 2 students is 51 kg; and that of other 2 students is 55 kg; then the average weight of all ten students combined is:
7
The average age of a class is 15.8 years. The average age of the boys is 16.4 years while that of the girls is 15.4 years. What is the ratio of boys to girls in the class?
The average age of 12 students in a class is 20 years. When 3 new studentsjoin the class, the average age of the class increases by 1 year. What is the average age of the 3 new students?
10
A class of 40 students took a test, and the average score was calculated to be 45. However, there were errors in recording some scores: 25 was mistakenly recorded as 35 twice, and 38 was mistakenly recorded as 32 once. What is the correct average score of the class?