The task is to generate the correct answer for a given math problem.

Problem: if each participant of a chess tournament plays exactly one game with each of the remaining participants , then 153 games will be played during the tournament . find the number of participants .
18

Problem: the ratio between b and y is 7 / 9 ; b and y are increased by 4 , what is the ratio between the new values of b and y ?
it can not be determine

Problem: in may , the groundskeeper at spring lake golf club built a circular green with an area of 65 π square feet . in august , the groundskeeper doubled the distance from the center of the green to the edge of the green . what is the total area of the renovated green ?

260 π