Mathematics

Problem

The sum of the series:

1 + \frac{1}{1+2} + \frac{1}{1+2+3} + \dots

up to 10 terms, is : [JEE-MAIN ONLINE - 2013] (1)

\frac{22}{13}

(2)

\frac{18}{11}

(3)

\frac{20}{11}

(4)

\frac{16}{9}