It’s 17 to 12 (Alternative clock system).

11:43

It’s 17 to 12.

Correct answer

11:42

It’s 18 to 12.

Error: 1 minute earlier

10:49

It’s 11 to 11.

Error: read minutes starting from hour markings and adding minutes

09:55

It’s 5 to 10.

Error: confuse hour and minute hands