Table:
0
A
B
C
D
E
F
1
Letters
Organization
Nickname
Founding Date
Founding University
Type
2
ΑΙΟ
Alpha Iota Omicron
"AIO"
1998-10-16
University of Michigan
Fraternity
3
ΒΧΘ
Beta Chi Theta 2
"Beta Chi/BCT"
1999-06-02
University of California, Los Angeles
Fraternity
4
ΒΚΓ
Beta Kappa Gamma
"BKG"
1999-05-06
University of Texas at Austin
Fraternity
5
ΔΣΙ
Delta Sigma Iota
"DSI"
2000-08-15
Pennsylvania State University
Fraternity
6
ΔΕΨ
Delta Epsilon Psi
"DEPsi/D.E.Psi"
1998-10-01
University of Texas at Austin
Fraternity
7
ΔΘΨ
Delta Theta Psi
"DTPsi"
2002-01-14
University of Michigan
Sorority
8
ΔΚΔ
Delta Kappa Delta 1
"DKD"
2000-08-15
Texas A&M University
Sorority
9
ΔEΣΙ
Delta Epsilon Sigma Iota
"Desi"
1997-12-12
University at Buffalo, SUNY
Fraternity
10
ΔΦΩ
Delta Phi Omega
"DPO"
1998-12-06
University of Houston
Sorority
11
ΙΝΔ
Iota Nu Delta
"IND"
1994-02-07
Binghamton University
Fraternity
12
ΚΦΓ
Kappa Phi Gamma
"KPhiG"
1998-11-08
University of Texas at Austin
Sorority

Questions and formulas:
Question: What organization had the founding date of 1998-11-08? 
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,D1="1998-11-08"),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F12,D2:D12="1998-11-08"),2))
Level: medium
Question: How many letters were given to the organization with a founding date of 1997-12-12? 
Formula: ROWS(UNIQUE(FILTER(A1, D1="1997-12-12")))
Formula2: ROWS(UNIQUE(FILTER(A2:A12, D2:D12="1997-12-12")))
Level: medium