Solution:The pattern followed here is :(1st number) ร 3 = (2nd number + 3rd number)
(13, 18, 21) โ 13 ร 3 = (18 + 21) = 39
(11, 25, 8) โ 11 ร 3 = (25 + 8) = 33
Similarly,
(14, 33, 9) โ 14 ร 3 = (33 + 9) = 42
Hence, (14, 33, 9) is the correct answer.