looking to find a way to make the right number appear within 6 seconds?
Let's go: If each number is available for 0.5s then you would need a sequence of 12 numbers to fill the time, right? (and your number must be within).
Generate an array of 12 random numbers and push your target number into a random position, then you just loop the array. Bingo, your target number will always be there.
I hope this idea can help you.