Question

find the sum 2+4+6....+200​

Answer 1

Sum of even numbers (Sn = n (n+1))

= 100(100+1)

= 100*101

= 10100

Answer 2

Answer:

The answer is 10100.

Step-by-step explanation:

Let the first term be 2 and last term be 200.

Then the common diffence be 4-2=2.

Now the a nterm is 200.

We have the formula to find the number of term that is

a nterm = a + (n-1).

=> 200 = 2 + (n-1)2

=> 198 =(n-1) 2

=> n-1 =99

=> n = 100

Now we put the another formula to find the sum it is

s nterm = n/2[2a+(n-1) d]

now put the value

=> 100/ 2 [ 2× 2 + ( 1oo - 1 ) 2]

=> 50 [ 4 + 99× 2 ]

=> 50 × 202

=> 10100

Hence the sum of given even number is 10100.