It’s 17 to 11 (Official clock system).

10:43

It’s 17 to 11.

Correct answer

10:42

It’s 18 to 11.

Error: 1 minute earlier

09:49

It’s 11 to 10.

Error: read minutes starting from hour markings and adding minutes

09:50

It’s 10 to 10.

Error: confuse hour and minute hands