How do I make timer start when in collusion with another object?

Hii, i am making quiz,in that project when the character collusion with another object the pop up question appear. i want make so that when pop up question appear a timer start, when player answer question timer stops.

This should help, not construct 3 , still events are the same

construct.net/en/tutorials/timers-278

I would do like this, example:

thanks a lot for the solutions!