I need help creating a timer

Good morning.

Can anyone help me to create a timer?

I am making times table game, which has 3 different levels.
first level - has no timer
second level - 10 seconds timer
third level - 5 seconds timer.

On each screen I have 3 answer buttons. I want timer to start when you press ‘play’ button, and I also want timer to reset, when user presses one of the answer buttons, and stops completely. The timer will start again, as well as the new question starts , and the same process repeats 8 times.

Can anyone help me with creating a timer and making it work as specified above?

Check out screen Flash Arena to see a timer in action

doesn’t work properly for me, a bit too slow

What is too slow? The timer? What does that mean

the app itself. I don’t understand how it works