The numbers which are multiple of 5 between 200 and 700 starts with 205 and ends with 695
205 , 210 , 215............,695
an=a+(n−1)d
Common difference, d=5
an=695(nthterm)
a=205(first term)
a+(n−1)d=995
205+(n−1)5=695
(n−1)5 = 695 - 205 = 490
n-1 = 490/5 = 98
n = 99
Sum = n/2 [ First term + Last term ]
= 99/2 [ 205 + 695 ]
= 99 × 900/2 = 44550
