Answer
10 meters
Work Step by Step
We use the equation for intensity to find the value of x, which we will call the distance that you need to be at:
$ x = r_{15}\sqrt{\frac{I_{15}}{I_x}}=15 \sqrt{\frac{750}{270}}= 25 m$
Subtracting this from where you started, we find:
distance $= 25-15=10\ m$
