Table:
0
A
B
C
D
1
thing id
date and date
status of thing code
timed status of things
2
2
2016-05-27 23:33:34
Open
3
2
2016-07-17 08:35:27
Close
4
2
2017-06-19 02:59:21
In Progress
5
10
2016-09-06 16:31:13
Close
6
10
2016-11-14 17:30:51
Open
7
14
2017-07-03 02:22:12
In Progress
8
26
2016-04-10 06:32:15
Close
9
26
2017-08-05 02:10:02
In Progress
10
26
2018-02-04 02:44:39
Close
11
35
2017-11-27 06:32:46
In Progress
12
47
2016-04-02 00:57:17
In Progress
13
47
2016-12-02 11:08:16
Close
14
58
2017-05-31 00:52:33
In Progress
15
80
2016-10-08 08:02:57
Open
16
84
2017-12-28 16:05:08
Open
17
85
2017-03-24 12:12:46
Close
18
92
2016-11-24 12:44:00
In Progress
19
92
2017-09-27 01:35:51
Close

Questions and formulas:
Question: How many different status codes of things are there?
Formula: ROWS(UNIQUE(C1))
Formula2: ROWS(UNIQUE(C2:C19))
Level: easy