We have to keep symbol into stack and when we get two operands followed by operator. We will apply operator on last two operands.$$\begin{array}{|ll|}\hline \textbf{symbol} & \textbf{stack } \\\hline \text{10} & \text{10 $\quad$ (keep in stack)}\\\hline \text{5} & \text{10 $\quad$ 5 $\quad$ (keep in stack)}\\\hline
\text{+} & \text{10 $\quad$ 5 $\quad$ + $\quad$ (apply operator on last 2 operands $\implies 10+5=15)$}\\\hline \text{60} & \text{15 $\quad$ 60 $\quad$ (keep in stack)}\\\hline \text{6} & \text{15 $\quad$ 60 $\quad$ 6 $\quad$ (keep in stack)}\\\hline
\text{/} & \text{15 $\quad$ 60 $\quad$ 6 $\quad$ / $\quad$ (apply operator on last 2 operands $\implies 60/6=10)$}\\\hline
\text{*} & \text{15 $\quad$ 10 $\quad$ * $\quad$ (apply operator on last 2 operands $\implies 10*15=150)$}\\\hline \text{8} & \text{150 $\quad$ 8 $\quad$ (keep in stack)}\\\hline - & \text{150 $\quad$ 8 $\quad -\quad$ (apply operator on last 2 operands $\implies 50-8=142)$}\\\hline \end{array}$$
So, answer is $142$.
