Simple it says you use 33 drops of yellow originally and 44 drops of blue it appears that each drops are 11 drops lesser (from blue to yellow). Therefore, add 11 to 1212 and you get your answer.
The correct answer is the second option: plus or minus square root of 20
Hope this helped :)
If you were at 54 on the number line you would have to cross zero and go an extra 13 steps to get to -13.
So we want the difference between 54 and -13 or 54- -13 which becomes 54+13 which is 67 - that is the range
