Yes you got it right because the formula is y=mx+b and the m is your slope.
This is not so much a calculable math problem as a common sense one. Based on your spending and income a 2 month fund pillow should be suffice. Don't hold me to this answer as you should decide this for yourself.
0.999998 meters are approximately in 39.37 metters
I think it is C-two real solution