The given sequence is a combination of two series: I. 13, 24, 35, 46, 57 and II. 32, 43, ?, 65, 76 The pattern in both I and II is + 11. So, missing term = 43 + 11 = 54.
The terms of the given series are numbers formed by joining together consecutive odd numbers in order i.e. 1 and 3, 3 and 5, 5 and 7, 7 and 9, 9 and 11, ..... So, missing term = number formed by joining 11 and 13 = 1113.