3 votes 3 votes Consider a $3$ digit number All digit are distinct Number is divisible by $7$ After reversing the digit number is also divisible by $7$. How many such numbers are possible? $4$ $5$ $6$ $7$ Quantitative Aptitude number-system divisibility + – Lakshman Bhaiya asked Feb 27, 2018 • edited Mar 11, 2018 by Sukanya Das Lakshman Bhaiya 1.1k views answer comment Share Follow See all 13 Comments See all 13 13 Comments reply ankitgupta.1729 commented Feb 27, 2018 reply Follow Share 4 ?? 0 votes 0 votes Lakshman Bhaiya commented Feb 27, 2018 reply Follow Share Yes 4 is the answer 0 votes 0 votes ankitgupta.1729 commented Feb 27, 2018 reply Follow Share @Srestha , All digits are distinct.. 0 votes 0 votes Tesla! commented Feb 28, 2018 reply Follow Share 168,259 and reverse of it also count as 3 digit numbers 0 votes 0 votes Tarun kushwaha 1 commented Feb 28, 2018 reply Follow Share but how to get 168, 259? 0 votes 0 votes Mk Utkarsh commented Feb 28, 2018 reply Follow Share https://math.stackexchange.com/questions/2348251/how-many-such-three-digit-numbers-are-possible 1 votes 1 votes Lakshman Bhaiya commented Feb 28, 2018 reply Follow Share Thanks Mk bhai 0 votes 0 votes Mk Utkarsh commented Feb 28, 2018 reply Follow Share i don't understand how people think like that :o check the answer bro :o 0 votes 0 votes Lakshman Bhaiya commented Feb 28, 2018 reply Follow Share Answer is 4 0 votes 0 votes Mk Utkarsh commented Feb 28, 2018 reply Follow Share yeah i know 0 votes 0 votes srestha commented Feb 28, 2018 reply Follow Share Actually there are 2 numbers 1x8, 2y9 and then their reverse And now by brute force put some value in x and y and check they are divisible by 7 or not Answer of stackoverflow some printing mistake is there it will be 168, 259,952,861 0 votes 0 votes Mk Utkarsh commented Feb 28, 2018 reply Follow Share yeah it should be 861 you're right he made a typo there 0 votes 0 votes Tesla! commented Feb 28, 2018 reply Follow Share If you haven't heard about it then only brute force can help you 0 votes 0 votes Please log in or register to add a comment.