Here is a set of basic questions producing integer or string outputs. Answer them and format the result precisely with the JSON instructions provided:

Question 0 (Question id: q_Tk696t):
Find the value of r in the equation: 640*r = 3200 Respond with an integer.

Question 1 (Question id: q_GoZEmy):
Your job is to return the last character of a string as a string. For example, the last char of "hello" is "o". Return the last character of the following string: "and"

Question 2 (Question id: q_hBWeE8):
Calculate ( 9 - -7 ).



Your output must be a JSON mapping every question id to its answer info.

The value for each key should be an object that contains the answer in the field 'answer'.
If the response to a question is an integer that is even, also add the field 'half_answer' to the object which contains the answer integer divided by two.
If the response to a question is a string, add a 'first_char' field containing its first character.

Now provide the result JSON using the described format.

{"ground_truth": {"q_Tk696t": {"answer": 5}, "q_GoZEmy": {"answer": "d", "first_char": "d"}, "q_hBWeE8": {"answer": 16, "half_answer": 8}}}