The pattern followed is, For 24: 4, 24 ÷ 4 = 6 As we can see 24 is divisble by 4 in the same way only 5 is given from which 45 is divisible. Similarly, For 45: ? 45 ÷ 5 = 9 5 is the only number among the given options, by which 45 is divisible. ‘5’ is related to the third number in the same way as the second number is related to the first number. Hence, “5” is the correct answer.