php random Query result changing when refreshing the page :X normal but not what i want

i'm working on a school project it's an online competition. i have lot of questions in a database table to be displayed in a page with a countdown to go to the next question when it ends. and the question is selected randomly. the problem is when i refresh the page the counter doesn't restart form begining (that's good for me) but the question changes . i want to know if there's a way to make the question doesn't change untill someone answer it (i have a boolean attribute of the question to see if it's used or not )