Diketahui	\(S\left( x \right) = \frac{{85 – x}}{{85 + x}},0 \le x \le 85\) \({}_t{p_x} = \frac{{85 – x – t}}{{85 + x + t}} \cdot \frac{{85 + x}}{{85 – x}}\)
Rumus yang digunakan	\({}_{\left. n \right\|m}{q_x} = {}_n{p_x} \cdot {}_m{q_{x + n}}\)
Proses pengerjaan	\({}_{\left. {35} \right\|15}{q_{15}} = {}_{35}{p_{15x}} \cdot {}_{15}{q_{50}}\) \(= {}_{36}{p_{15}} \cdot \left( {1 – {}_{14}{p_{51}}} \right)\) \(= \frac{{85 – 15 – 36}}{{85 + 15 + 36}} \cdot \frac{{85 + 15}}{{85 – 15}} \cdot \left( {1 – \frac{{85 – 51 – 14}}{{85 + 51 + 14}} \cdot \frac{{85 + 51}}{{85 – 51}}} \right)\) \(= \frac{{34}}{{136}} \cdot \frac{{100}}{{70}} \cdot \left( {1 – \frac{{20}}{{150}} \cdot \frac{{136}}{{34}}} \right)\) \(= \frac{1}{6}\)
Jawaban	b. 1/6