The line bx +ay=3ab cuts the coordinate axes at A and b then centroid of triangleOAB is

On constructing this on Cartesian plane we find that y intercept is 3b and x intercept is 3a ( by x=0,y=0) triangle OAB is right angle triangle so just use x(centroid)=(3a+0+0)/3and y coordinate is y= (3b+0+0)/3. So coordinates of centroid is (a,b). if answer is wrong then just mail me