Among three numbers, the first is twice the second and thrice the third. If the average of the three numbers is 49.5, then the difference between the first and the third number is: 

The average of runs scored by a cricketer in his 99 innings is 99. How many runs will he have to score in his 100th innings so that his average of runs in 100 innings will become 100?

The average of a collection of 20 measurements was calculated to be 56 cm . But later it was found that a mistake had occurred in one of the measurements which was recorded as 64 cm, but should have been 61 cm. The correct average must be: 

A librarian purchased 60 story books for his library. But he found that he could get 4 extra books by spending Rs. 336 more and then the overall average price per book would be reduced by Re 1. The previous average price of each book was 

The average monthly income of x and y is 5050. The average monthly income of y and z is 6250 and the average monthly income of x and z is 5200. The monthly income of x is?

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 weight of A B and C is 50 kg . if the average weight of A and B be 48 kg and that of B and C be 45 kg , then find the weight of B ?

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?