1. **Problem statement:** We have a one-dimensional array $A$ with elements $A[1], A[2], \ldots, A[n]$ where $n = 50$. 2. **Part a:** How many elements are in the array? - The array has $n = 50$ elements. 3. **Part b:** How many elements are in the subarray $A[4], A[5], \ldots, A[39]$? - Number of elements = $39 - 4 + 1 = 36$. 4. **Part c:** If $3 \leq m \leq n$, what is the probability that a randomly chosen element is in the subarray $A[3], A[4], \ldots, A[m]$? - Number of elements in subarray = $m - 3 + 1 = m - 2$. - Total elements = $n$. - Probability = $\frac{m - 2}{n}$. 5. **Part d:** What is the probability that a randomly chosen element is in the subarray $A[\frac{n}{2}], A[\frac{n}{2} + 1], \ldots, A[n]$ if $n = 39$? - Start index = $\frac{n}{2} = \frac{39}{2} = 19.5$, round up to 20 since indices are integers. - Number of elements = $n - 20 + 1 = 20$. - Probability = $\frac{20}{39}$. **Final answers:** - a) 50 - b) 36 - c) $\frac{m - 2}{n}$ - d) $\frac{20}{39}$