And what I need more information to answer your question.
Answer:
25%
Step-by-step explanation:
Discount = 1600 - 1200 = 400
Percentage discount

C. For every decrease of one chore completed, one hour was spent on the internet.
Answer:
Undefined
Step-by-step explanation:
A slope is found using the formula rise (change in y) over run (change in x). The change in x is 0, and the change in y is -2. The answer is -2/0, but dividing by 0 gives you undefined. Don't believe me? Look at the attached image.
Hope this helps!