Question 58
In the space a geometrical configuration, which includes $n$ ($n \geq 3$) distinct points, is given. A point $A$ of this configuration has the following properties: if $A$ is excluded from the configuration, then among the remaining points there are no colinear points; after the elimination of $A$ from the configuration the number of all straight lines, that were constructed through any 2 points of the configuration, is lowered by $1/15$ part. Find the value of $n$.