# Write a java program to find average of prime locations.

Write a program to read an integer array and find the average of the numbers located on the Prime location(indexes).

- Round the average to two decimal places.
- Assume that the array starts with index 0.
- The return type (double) should be the average

**Input and Output Format:**

Input consists of n+1 integers. The first integer corresponds to n, the number of elements in the array. The next ‘n’ integers correspond to the elements in the array.

- Output consists of a single Double value.
- Refer to sample output for formatting specifications.
- Assume that the maximum number of elements in the array is 20.

**Find the average of prime locations in Java.**

import java.text.DecimalFormat; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int[] a = new int[20]; int n = sc.nextInt(); for (int i = 0; i < n; i++) { a[i] = sc.nextInt(); } System.out.print(display(n, a)); } public static double display(int n, int[] a) { int count = 0, sum = 0, n1 = 0, d = 0; int count1 = 0; double avg = 0; for (int i = 2; i < n; i++) { count = 0; for (int j = 1; j <= i; j++) { if (i % j == 0) { count++; } } if (count == 2) { sum = sum + a[i]; count1++; } } avg = (double) (sum) / count1; DecimalFormat df = new DecimalFormat("#.00"); double ddd = Double.parseDouble(df.format(avg)); return ddd; } }

**Sample Input 1:**

8

4

1

7

6

5

8

6

9

**Sample Output 1:**

7.5