The proportional relation between two variable with constant of proportionality equal to 5 is,
For x = 5,
(5,1) not lies on the line as for x = 5, the y is 25.
For x = 3,
The point (3,15) lies on the line.
For x = 10
Point (10,2) not lies on the line.
For x = 0,
The point (0,5) not lies on the line.
So point (3,15) lie on the line.