Table:
0
A
B
C
D
E
1
Class
Type
Built
Number
Withdrawn
2
Class 170 Turbostar
diesel multiple unit
1999–2004
4
2005
3
Class 222 Pioneer
diesel multiple unit
2005
4
2009
4
Class 86
Electric locomotive
1965–1966
1
2008
5
Mark 3 Carriage
Passenger Carriage
1975–1988
5
2008
6
Mark 3 Carriage
Driving Van Trailer
1988
1
2008

Questions and formulas:
Question: Which class had a number under 4 and was built in 1988?
Formula: LET(query1,LET(query1,FILTER(A1:E1,C1=1988),SUMMARIZE(CHOOSECOLS(query1,1),SUMX(CHOOSECOLS(query1,4)))),FILTER(query1,CHOOSECOLS(query1,2)<4))
Formula2: LET(query1,LET(query1,FILTER(A2:E6,C2:C6=1988),SUMMARIZE(CHOOSECOLS(query1,1),SUMX(CHOOSECOLS(query1,4)))),FILTER(query1,CHOOSECOLS(query1,2)<4))
Level: hard
Question: How many items withdrawn had numbers over 5?
Formula: ROWS(UNIQUE(FILTER(E1, D1>5)))
Formula2: ROWS(UNIQUE(FILTER(E2:E6, D2:D6>5)))
Level: medium
Question: What is the sum of numbers that had a type of Driving Van Trailer?
Formula: SUMIFS(D1,B1,"driving van trailer")
Formula2: SUMIFS(D2:D6,B2:B6,"driving van trailer")
Level: easy