Not able to figure out the favorable vs total outcomes

Hey Guys,

Another probability problem. I am not able to figure out the right values to use for favorable outcomes.

In a medical experiment, some students who suffered from stress were given the drug "StressOff" while others were given "Placebo". The proportions in different categories are given below.

- Find the value of p.
- Find the probability that a student chosen at random

- Took the drug "StressOff" but did not improve,
- did not improve at all
- improved given that he or she took the drug "Placebo"

(I)

These are percentages so,

(II-a)

This is wrong, the required answer is 0.32. When calculating probability of not improve, are the favorable outcomes out of only people part of the StressOff group?

(II-b)

This is the only thing I have got right in this problem!

(II-c)

Again incorrect, the required answer is 0.15

Any inputs to help me figure out what I did wrong here would be greatly appreciated. Thanks.