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

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 5 numbers, arranged in a row, is 309. The average of the first two of these numbers is 431 and the average of the last two of these numbers is 231.5. What is the value of the number at the center of the row?

In a year, the average expenditure of a family for the first 3 months, next 4 months and last 5 months is Rs 8400 per month, Rs 10080 per month, Rs 10608. Monthly and annual savings are Rs. 8640. If so, what is the average monthly income of this family?

What is the average of all odd natural numbers less than 100?

Average age of x students in a group is 20. When 4 new students are admitted with a age of 7.5 years each, then the average is decreased by 5. What is the value of x?

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 

A batsman scores 98 run in the 17^th match of his career. His average runs per match increased by 2.5. What is his average before the 17^th match?