It’s 18 to 10 (Alternative clock system).

09:42

It’s 18 to 10.

Correct answer

09:43

It’s 17 to 10.

Error: 1 minute later

08:50

It’s 10 to 9.

Error: read minutes starting from hour markings and adding minutes

08:45

It’s a quarter to 9.

Error: confuse hour and minute hands