find the 3D coordinate of point with condition

Let's say: I have point A(1,1,1) in 3D space OXYZ, and vector n(1,2,3). How can i find the coordinate point B satifying the condition:

1/ Distance between A & B is: 10

2/ B lie on vector n

Answer 1

[Matt J]

B=A+10*n/norm(n);

or

 B=A-10*n/norm(n);