Answer:
3900
Step-by-step explanation:
We want the sum from 5 to 195
5, 10, 15, 20,......195
an = 5 + 5(n-1) since we can write this as an arithmetic sequence, adding 5 each time
The sum of the terms of an arithmetic sequence is given by
Sn = n/2 [2a1 + (n - 1)d],
where d is the common difference of 5 and n is the term we want to add to
195/5 = 39 so it is the 39th term
s39 =39/2 [2*5 + (39-1)*5)]
s38 = 19.5[10+38*5]
=19.5*[10+190]
19.5*200
=3900
