(i) Number of balls which are not red =18−x P( ball not red )= 1818−x​(ii) When 2 red balls are added, then Total number of balls =20, red balls =x+2P( Red ball )=20x+2​According to the question :P( Red ball ) =89​P( ball not red in first case)⇒20x+2​=89​×18x​⇒36x+72=45x⇒x=8