I personally would probably use one or more text display questions on the last page before the end message, but I guess this is personal taste.
To your code: This looks pretty good already, but if you do not have values below 0 in your scale / assessment values, you could just skip that part and ask for <10, which would include 0-9. Makes the code shorter and cleaner and you don't need the AND connection.
After that you would write the text that you want. For each scale I would create nested IF loops.
So the IF loops are usually structured this way: if(formula to check, what to do, what to do else), so here is what you could do:
Code:
{if(BPD.value < 10, "You have scored between 0-9",
if(BPD.value < 20, "You have scored between 10-19",
if(BPD.value < 30, "You have scored between 20-29", "You have scored between 30-40")
)
)
}
This isn't tested and it is assuming that the scale ends with 40. But I think you get the idea. There might be more elegant solutions. Give it a try. Maybe first test with a few ranges to see if and how it works, then go for the whole scale (I assume you go from 1-100?).