Question

The radius of any circle touching the lines $3x-4y+5=0$ and $6x-8y-9=0$ is:

• A. 1.9
• B. 0.95
• C. 2.9
• D. 1.45
• E. 1.95

Answer 1

Answer: (B)

Distance between the lines $3x-4y+5=0$ and $6x-8y-9=0$ is $\left|\frac{5+\frac{9}{2}}{\sqrt{3^2+4^2}}\right|=\left(\frac{19}{10}\right)=1.9$ is the diameter of circle $\therefore$ Radius of circle $=\frac{1.9}{2}=0.95$