Table:
0
A
B
C
D
E
F
1
Day 1
Day 2
Day 3
Day 4
Day 5
Wednesday
2
Math
Fr.
Math
Math
Math
9:00–10:08
3
PAAQ
PAAQ
PAAQ
PAAQ
PAAQ
No PAAQ
4
P.E.
P.E.
Fr.
P.E.
P.E.
10:22–11:30
5
Sc.
Eng.
Sc.
Fr.
Eng.
12:30–1:38
6
Eng.
Sc.
Eng.
Sc.
Fr.
1:52–3:00

Questions and formulas:
Question: What is day 4 when day 2 is PAAQ?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,B1="paaq"),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F6,B2:B6="paaq"),4))
Level: medium