List the multiples of 3:
3, 6, 9, 12, 15, 18,21
The ones between 10 and 20 are:
12, 15, 18
The range is the difference between the highest and lowest numbers.
Range = 18 - 12 = 6
Answer:
D. 6
Step-by-step explanation:
Let's first find x :-

Now that we found x, let's find QR :-
QR = 2x + 22
Therefore, QR = 6 !!!
I'm gonna go with D. I really hope that's right math isn't my strong suit lol