IBPS Clerk Prelims 2015 Paper

(a) If the positions of only the second and the third digitswithin each number are interchanged, the numbersbecome as follows.
571   352   693   814   729
Now, when the numbers are arranged in descendingorder, we get
814   729   693   571   352
Here, 729 is the second highest number
Hence, the first digit of 729 is 7.