Skip to main content

sum of even numbers from 2 to 100

Even numbers from 2 to 100
Even numbers are 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,    54, 56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96,98,100.
Now we will see the sum of elements:
Sum of first 2 even numbers: 2+4= 6
The above can be written as
Sum of first 2 even numbers: 2+4= 6= 2x3=2(2+1)
Sum of first 3 even numbers: 2+4+6= 12= 3(3+1)
Sum of first 4 even  numbers: 2+4+6+8=20= 4(4+1)
Sum of first 5 even numbers: 2+4+6+8+10 = 30 = 5(5+1)
Sum of first n even numbers: 2+4+6+8+10+. . . . .  n numbers= n(n+1)

Sum of  even numbers from 2 to 100 = 2+4+6+8+10+. . . . .  50 numbers                                                                           = 50(50+1)
                                                                =50x51
                                                                =2550

Comments

Popular posts from this blog

pythagoras triangle numbers from difference between two adjacent numbers

1 2 =1x1=1                           ---->3 2 2 =2x2=4                           ---->5 3 2 =3x3=9                           ---->7 4 2 =4x4= 16                           ----> 9 --->(pythagoras numbers 16+9=25 ==>  4 2 +3 2   = 5 2 ) 5 2 =5x5= 25                           ---->11  6 2 =6x6=36            ...

pythagaraus traingle numbers uptp 100 square numbers

-------------------------------------------------------------------------------------------------------------------------- 4 2 =4x4= 16                           ----> 9 --->(pythagoras numbers 16+9=25 ==>  4 2 +3 2   = 5 2 ) 5 2 =5x5= 25 -------------------------------------------------------------------------------------------------------------------------- 12 2 =12x12= 144                           ----> 25 --->(pythagoras numbers 144+25=169 ==> 12 2 +5 2   =13 2 ) 13 2 =13x13= 169 -------------------------------------------------------------------------------------------------------------------------- 24 2 =24x24= 576                 ...

Time when the hands of the clock meet together.

In all competitive exams questions on clock are common In this we will dicuss on question. At what time the hands of a clock be together?. The explanation for this question is Given in below table. Sl No Hours Fraction part Fraction part simplified Time when the hands of a clock meet together 1 1-2 60/11 5    5/11 5    5/11 min past 1 2 2-3 120/11 10  10/11 10  10/11 min past2 3 3-4 180/11 16   4/11 16   4/11 min past 3 4 4-5 240/11 21  9/11 21   9/11 min past 4 5 5-6 300/11 27  3/11 27   3/11 min past 5 6 6-7 360/11 32  8/11 32   8/11 min past 6 7 7-8...