# 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;
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