The average of 30 numbers is 15. The average of the first 18 numbers is 10 and that of the next 11 numbers is 20. The last number is

The average of nine numbers is 50. The average of first five numbers is 54 and that of the last three numbers is 52, then the sixth number is -

The average expenditure of a man for the first five months of a year is Rs. 5,000 and for the next seven months is Rs. 2,300 during a year. His average monthly expenditure is : 

A cricketer's average score in 10 innings was 36. In his 11th innings, he scored some runs because of which his average increased to 40. What was his score in 11th innings?

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 present age of a father is 3 years more than three times the age of his son. Three years hence, father's age will be 10 years more than twice the age of the son. The father's age is: 

The average of three numbers is 40. The first number is twice the second and the second one is thrice the third number. The difference between the largest and the smallest numbers is

The average of 5 consecutive natural numbers is M. If the next three natural numbers are also included, how much more than M will the average of these 8 numbers be?