The average age of three boys is 15 years if their ages are in the ratio 3 : 5 : 7, what will be the age of the youngest boy?

The average marks of 32 boys of section A of class X is 60 whereas the average marks of 40 boys of section B of class X is 33. The average marks for both the sections combined together is 

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

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____

The heights of six people are given as 6 feet 6 inches, 6 feet, 5 feet 8 inches, 6 feet 2 inches, 6 feet 4 inches, and 5 feet 10 inches, respectively. Find the average height of these six people.

If the average marks of three batches of 30, 50 and 70 students is 55, 70 and 70 respectively, then the average marks of all the students is:

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?