Average of 21 number is 36. If the average of first 12 numbers is 15, then find the average of remaining 9 number?

The average of six numbers is 3.52. The average of two of them is 3.7, while the average of other two is 2.5. What is the average of the remaining two?

The average of 5 numbers is 27. If one number is excluded, the average becomes 25. The excluded number is: 

A man purchased 7 bags of rice at the rate of  ₹ 800 each, 8 bags of rice at ₹ 1000  each and 5 bags of rice at the rate of  ₹ 1200 each. What is the average cost of one bag of rice?

The average of three numbers a, b and c is 2 more than c. The average of a and b is 48. If d is 10 less than c, then the average of c and d is:

The average of the largest and smallest 3 digit numbers formed by 0, 2 and 4 would be 

The average salary per head of all the workers of JK Campus is ₹ 60. The average salary of 12 center heads is ₹ 400 and of the rest is ₹ 56. The total number of workers in JK Campus is 

The average salary of the entire staff in an office is Rs 3200 per month. The average salary of officers is Rs 6800 and that of non-officers is Rs 2000. If the number of officers is 5, then find the number of non-officers in the office.