**Average (Quantitative Aptitude) for Bank PO, Clerk, SSC CHSL, CGL and other competitive exams Weighted Average and Average Speed**

The average of a given set of number is a measure of the central tendency of the set. In other words, it is the mean value of a set of number or values. Therefore, average of a set of given n number is given by (

*x*1+

*x*2+

*x*3+-----+

*xn*)/n.

Average of some observation = sum of all observation/no of all observation.

**Weighted Average**

*n*, quantities is

*x*and that of

*n*2 quantities is

*y*, the average of total (

*n*1+

*n*2) quantities is given by.

*n*1

*x*

+

*n*2/*n*1 +*n*2**Average Speed**

• Average speed = Total distance/Total time

The distance between two points A and B is d and speed is travelling from point A to B is x km/h and from point B to A is

*y*km/h.
Then, Average speed = 2

*xy*/*x+y*

**Average of some important series of numbers**

- Average of odd numbers from 1 to
*n*= (*n*+1)/2 , where n = last odd number.

- The average of even number from 2 to
*n*= (*n*+ 2)/2,when n = last even number.

- The average of square of natural numbers till.
*n*= (*n*+1) (2*n*+1)/6.

- The average of cubes of natural number till
*n*= [*n*(*n*+ 1 )2].

- The average of first
*n*consecutive odd number =*n*

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