First Number × 2 = Second Number (First‌Number)2 = Third Number In (7 ,14 , 49 ) → First Number = 7 Second Number = 7 × 2 = 14 Third Number = 72 = 49 In (9,18, 81 ) → First Number = 9 Second Number = 9 × 2 = 18 Third Number = 92 = 81 Hence, the correct answer is "(9, 18, 81)".