Chapter 9.3, Problem 3CP

In a biased random walk, the probability of going up one unit is $0<p<1$, and the probability of going down one unit is $q=1-p$ . Design a Monte Carlo simulation with $n=\text{1}0000$ to find the probability that the biased random walk with $p=0.7$ on the interval in Computer Problem 1 reaches the top. Calculate the error by comparing with the correct answer $\left[{\left(q/p\right)}^b-1\right]/\left[{\left(q/p\right)}^{a+b}-1\right]$ for $p\ne q$.