For every positive integer n, the nth term of sequence is given by an= 1/n - 1/(n+1). What is the sum of the first 70 terms?
Choose the correct choice from the following choices.
A) 3/5 B) 7/15 C) 35/36 D) 70/71 E) 140/141
a1 = 1 - 1/2   a2 = 1/2 - 1/3   a3 = 1/3 - 1/4   etc...   a70 = 1/70 - 1/71   The sum of these terms is 1-1/71 = 70/71   The answer is 70/71.
<result>D</result>
For every positive integer n, the nth term of sequence is given by an= 1/n - 1/(n+1). What is the sum of the first 70 terms?