Solution:The pattern followed here is :(1st number ร 2nd number) + 5 = 3rd number
(12, 11, 137) โ (12 ร 11) + 5 โ 132 + 5 = 137
(17, 21, 362) โ (17 ร 21) + 5 โ 357 + 5 = 362
Similarly,
(21, 25, 530) โ (21 ร 25) + 5 โ 525 + 5 = 530
Hence, (21, 25, 530) is the correct answer.