In a school , 391 boys and 323 girls have been divided into the largest possible equal classes , so that each class of boys numbers the same as each class of girls . What is the number of classes ?
2. In a class of 66 students there are 33 girls. The average weight of these girls is 61 Kg and average weight of the full class is 66 kgs. What is the average weight of the boys of the class?
3. The average revenues of 7 consecutive years of a company is Rs 75 lakhs. If the average of first 4 years is Rs 70 lakhs and that of last 4 years is Rs 82 lakhs, what will be the revenue for the 4th year.
4. The mean of marks secured by 60 students in division A of class X is 64, 40 students of division B is 60 and that of 60 students of division C is 58. Find the mean of marks of the students of three divisions of Class X.
5. The mean of marks secured by 55 students in division A of class X is 58, 45 students of division B is 54 and that of 75 students of division C is 52. Find the mean of marks of the students of three divisions of Class X.
6. The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observations is
7. 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:
8. A student, by mistake, wrote 64 in place of 46 as a number at the time of finding the average of 10 given numbers & got the average as 50. The correct average of the numbers is
9. The average cost of 4 items in a shopping list is Rs 1,250. If one more item whose cost is Rs 2,000 is added to the list what will be the new average (in Rs)?
10. The average marks of 10 students in an examination was 25. It was later found that the marks of one student had been wrongly entered as 34 instead of 43. What is the correct average?