Table:
0
A
B
C
D
E
F
1
geohash length
lat bits
lng bits
lat error
lng error
km error
2
1
2
3
±23
±23
±2500
3
2
5
5
± 2.8
± 5.6
±630
4
3
7
8
± 0.70
± 0.7
±78
5
4
10
10
± 0.087
± 0.18
±20
6
5
12
13
± 0.022
± 0.022
±2.4
7
6
15
15
± 0.0027
± 0.0055
±0.61
8
7
17
18
±0.00068
±0.00068
±0.076
9
8
20
20
±0.000085
±0.00017
±0.019

Questions and formulas:
Question: What is the lowest geohash length when the lat bits are less than 7, and the km error of ±2500?
Formula: MIN(FILTER(A1, (B1<7)*(F1="±2500")))
Formula2: MIN(FILTER(A2:A9, (B2:B9<7)*(F2:F9="±2500")))
Level: easy
Question: What is the highest geohash length when the lat error is ±0.00068, and the lat bits larger than 17?
Formula: MAX(FILTER(A1, (D1="±0.00068")*(B1>17)))
Formula2: MAX(FILTER(A2:A9, (D2:D9="±0.00068")*(B2:B9>17)))
Level: easy
Question: What is the highest geohash length when there is a ng error of ±0.00017, and a lng bits smaller than 20?
Formula: MAX(FILTER(A1, (E1="±0.00017")*(C1<20)))
Formula2: MAX(FILTER(A2:A9, (E2:E9="±0.00017")*(C2:C9<20)))
Level: easy