Question

the sum of even numbers between 100,200 is​

Answer 1

Answer:

The even number between 100-200 is 102,103,104,....,194,196,198

a=102             d=2             An=198

An=a+(n-1)d

198=102+(n-1)2

(n-1)2=198-102

(n-1)2=96

n-1=96/2

n-1=48

n=48+1

n=49

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

Sn=49/2[102+(49-1)2]

Sn=49/2[102+48*2]

Sn=49/2[102+96]

Sn=49/2[198]

Sn=49*99

Sn=4851