Answer :
Explanation :

It is given that the first digit is 1/3 of the second. There are 3 such possibilities 1)1 and 32)2 and 63)3 and 9 Now, the third digit is the sum of the first and second digits.1)1 + 3 = 4 2)2 + 6 = 83)3 + 9 = 12It is clear that option 3 is not possible. So we are left with only two options. Also, the last digit is three times the second, which rules out the second option. Hence, the answer is 1349.