IBPS - QUANTITATIVE APTITUDE - THE ADDITION

                               THE ADDITION

Rule 

    Sum of Consecutive n-Natural Numbers:

Formula

             The sum of consecutive n-natural numbers=

Example 1

             1+2+3+4+5+..........+20=?

Here n=20

 

Example 2

    1+2+3+4+5+.......+50=?

Here n=50

Rule

       Sum of Terms

       The sum of the terms =

Example 1 

       Give the sum of the terms=?

       Here x=2 and n=10, then

Sum==110

Example 2

       Give the sum of the terms=?

      Here x=4 and n=20, then

Sum==840

Rule

 Sum of Square of Consecutive n-Natural Numbers

Sum of the squares of consecutive n-Natural Number=

Example 1

           =?

here n=20

Then sum= 

                       =2840

Rule

  Sum of Cubes

Sum of the cubes of consecutive n-Natural Number=

Example 1

  

=?

here n=10

Thus sum ==3025

Rule : Sum of Even Number

   Sum of the consecutive n-even no=x(x+1)

Here x= 

Example 1

          2+4+6+8+10=?

here n=10 and then x=5

Thus sum=5(5+1)=30

Example 2

      Give sum of consecutive 10 even nos.?

here x=10

and then sum=10(10+1)=110

Note : There is a difference. If we say sum of consecutive 10 even numbers. This means that 2+4+6+8+10+12+14+16+18+20. This sum is 10(10+1)=110.But if we say the sum of consecutive even numbers till 10.Then this means 2+4+6+8+10.This sum is n=10 and x===5.

5(5+1)=30.

   This is main difference between sum of consecutive 10 even nos. and sum of consecutive even nos. till 10.

Rule : Sum of odd Numbers

The sum of Consecutive n-odd number=

Example 1

   1+3+5+7+9+11=?

here=n=11     sum==36.

Example 2

             Give sum of consecutive odd number till 11.

sum==121

Note: The difference between consecutive 11 odd No. means 1+3+5+7+9+11+13+15+17+19+21 and consecutive odd numbers till 11 means 1+3+5+7+9+11.

Rule :

       The sum of series in which the difference between two consecutive terms are same=

Example 1

                3+8+13+18+23+28+33=?
The difference between two terms

                    =8 - 3 = 13 - 8=18 - 13=........=5
First term =3, Last term=33, No. of terms=7

Sum= =126

Exercise

1.   339.001 + 9.62 + 0.02 + 0.132 + 187=?

     

       (1)  525.773   (2)  535.723  (3)  535.773

       (4)  532.733    (5)  None

2.   0.0002 + 2.02 + 2.0002 + 3.002 + 2222=?

     

       (1)  2119.0124   (2)  2229.0224  (3)  2129.0224

       (4)  2228.0224   (5)  None

3.   1 + 2  +  3 + 4 + 5 +.................+ 22=?

     

       (1)  253   (2) 254  (3)  251  (4)  250  (5)  None

4.  = ?

       (1)  200   (2) 201  (3)  202  (4)  204  (5)  None

  
5.  = ?

       (1)  1920   (2) 1295  (3)  1296  (4)  1290  (5)  None

6.   10 + 12 + 14 + 16 + 18 + 20 + 22 + 24 =? 

     

      (1)  130   (2) 135  (3)  132  (4)  136  (5)  None