No prob, i proceed to AC now.

I guess, Test 6 is:

T != 0.0
V != 0.0
p == 0.0
n - ?

Ans: n = 0 (just 0, not 0.000000)

T != 0.0
V != 0.0
n == 0.0
p - ?

Ans: same here, p = 0

your answer is wrong . because it becomes T != 0 and V != 0 and n == 0 answer is error!
i think answer is "error" when n != 0 and p == 0 or p != 0 and n == 0 ...