The average of 5 consecutive even numbers is A. If next 5 even numbers are also included, then what is the average of these 10 numbers?

The average mathematics marks of two Sections A and B of class IX 131 the annual examination is 74. The average marks of Section A is 77.5 and that of Section B is 70. The ratios of the number of students of Section A and B is:

Total weekly emoluments of the workers of a factory is 1534. Average weekly emolument of a worker is 118. The number of workers in the factory is:

The average of 10 observations is 21. A new observation is included and the average of these 11 numbers is 1 less than the prevoius average. The 11^th observation is____

 In a family, the average age of a father and a mother is 35 years. The average age of the father, mother and their only son is 27 years. What is the age of the son? 

The average weight of 12 parcels is 1.8 kg. Addition of another new parcel reduces the average weight by 50 g. What is the weight of the new parcel?

The average of four consecutive even numbers is 9. Find the largest number. 

There are two groups A and B of a class, consisting of 42 and 28 students respectively. If the average weight of group A is 25 kg and that of group B is 40 kg, find the average weight of the whole class.