Question

Distance between the points $(2,3,5)$ and $(4,3,1)$ is $a\sqrt{5}$. The value of ' $a$ ' is

• A. 2
• B. 3
• C. 9
• D. 5

Answer 1

Answer: (A)

The given points are $(2,3,5)$ and $(4,3,1)$.
$\therefore$ Required distance $=\sqrt{(4-2{)}^2+(3-3{)}^2+(1-5{)}^2}$
$=\sqrt{4+0+16}=\sqrt{20}=2\sqrt{5}$