A1,A2,A3,...An are n points in a plane whose coordinates are (x1,y1), $(x_{2}, y_
{2}),(x_{3}, y_{3})...,(x_{n}, y_{n})$ respectively.
If
x1=a,y2=b;x1,x2,...xn and
y1,y2,...yn form an ascending arithmetic progression with common difference
2 and
4 respectively, then the coordinates of
G in
Q1 are