1).

The user expects this to create a Scanner from the filename "test.dat".
Unfortunately, Java doesn't do that -- it creates a Scanner from the
literal String "test.dat" instead of opening a File.

2).

(B) -- We successfully create a scanner reading the file by
  1] creating a new File from "example.txt"
  2] creating a new Scanner from that File
  3] assigning the resulting Scanner to a Scanner variable, input

3).

(B) -- Tokens are delimited by whitespace.

4).

(D) -- All variable declarations have
   1] a type
   2] a name
   3] an assignment to a right-hand-side expression (optional)

5).
   a] numbers[0]
   b] numbers[9] (since the length is 10 we know the valid index range is 0-9
   c] numbers[numbers.length - 1]

6).

int low = 6;
int high = 38;
int low_odd = low % 2;
int high_odd = high % 2;
int dist = (high - low + 1 + low_odd + high_odd) / 2;

int[] odd = new int[dist];
int index = 0;
for (int num = low + (1 - low_odd); num <= high; num += 2) {
    odd[index] = num;
    ++index;
  }
}

7).

int[] numbers = new int[8];

+--+--+--+--+--+--+--+--+
| 0| 0| 0| 0| 0| 0| 0| 0|
+--+--+--+--+--+--+--+--+

numbers[1] = 4;

+--+--+--+--+--+--+--+--+
| 0| 4| 0| 0| 0| 0| 0| 0|
+--+--+--+--+--+--+--+--+

numbers[4] = 99;

+--+--+--+--+--+--+--+--+
| 0| 4| 0| 0|99| 0| 0| 0|
+--+--+--+--+--+--+--+--+

numbers[7] = 2;

+--+--+--+--+--+--+--+--+
| 0| 4| 0| 0|99| 0| 0| 2|
+--+--+--+--+--+--+--+--+

int x = numbers[1];
// x is now 4

numbers[x] = 44;

+--+--+--+--+--+--+--+--+
| 0| 4| 0|44|99| 0| 0| 2|
+--+--+--+--+--+--+--+--+

numbers[numbers[7]] = 11;
// numbers[7] is 2

+--+--+--+--+--+--+--+--+
| 0| 4|11|44|99| 0| 0| 2|
+--+--+--+--+--+--+--+--+