Countdown timer for use in a non-quiz slide

Hello! I have read many threads about countdown timers, however I am still very new to Storyline and I am unsure about using variables. I want to insert a countdown timer on a slide that poses three separate questions, one at a time. The timer would countdown from 10 seconds to 0 to allow the user to reflect on the question asked. They would not enter an answer. 

I would appreciate some expert advice! :) Thanks!