Seven years ago, the average age of A, B and C was 51 years. If A is 3 years older than B and B is 3 years older then C then the present ages of A, B and C are ( in year)
1. Nine students of a class contribute a certain sum of money. Seven of them gave Rs. 50 each and the other two gave respectively Rs. 50 and Rs. 90 more than the others. The average contribution of the class of 9 students is
2. 19 persons went to a hotel for a combined dinner party. 13 of them spent Rs 79 each on their dinner and the rest spent Rs 4 more than the average expenditure of all the 19. What was the total money spent by them?
3. The average of fruits offered in a temple in a week was 75. The average of fruits offered in six days excluding Tuesday was 72. How many fruits were offered on Tuesday?
4. The mean of 21 observations (all different) is 40. If each observation greater than the median is increased by 21, then the mean of observations will become:
5. In a class of 60 students there are 30 girls. The average weight of these girls is 58 Kg and average weight of the full class is 63 kgs. What is the average weight of the boys of the class?
7. The average salary of all workers in a workshop is Rs.12000. The average salary of 7 technicians is Rs.15000 and the average salary of the rest is Rs.9000. The total number of workers in the workshop is
8. The average of 21 numbers is 12. The average of the first 11 numbers is 9 and the average of the last 11 numbers is 15. What is the value of the middle number?