Chapter 14 - Sequences, Series, and the Binomial Theorem - 14.1 Sequences and Series - 14.1 Exercise Set - Page 894: 27

$a_{1}=\frac{1}{1+1}=\frac{1}{2}$ $a_{2}=\frac{2}{2+1}=\frac{2}{3}$ $a_{3}=\frac{3}{3+1}=\frac{3}{4}$ $a_{4}=\frac{4}{4+1}=\frac{4}{5}$ $a_{10}=\frac{10}{10+1}=\frac{10}{11}$ $a_{15}=\frac{15}{15+1}=\frac{15}{16}$

If we want to find a term, we have to substitute $n$ by its index: $a_{1}=\frac{1}{1+1}=\frac{1}{2}$ $a_{2}=\frac{2}{2+1}=\frac{2}{3}$ $a_{3}=\frac{3}{3+1}=\frac{3}{4}$ $a_{4}=\frac{4}{4+1}=\frac{4}{5}$ $a_{10}=\frac{10}{10+1}=\frac{10}{11}$ $a_{15}=\frac{15}{15+1}=\frac{15}{16}$