there is number X in decimal represntation whose last digit is not 0. if digits of X are reversed then we obtain new number say Y. both X and Y are divisible by 7. then find all such X from 10 to 1000.

3 Answers on this Question

1. consider any 3 digit number first…
   100a+10b+c
   reverse it-
   100c+10b+a
   if these two numbers are divisible by 7 even their
   difference must be
   so
   99(a-c) is div by 7
   -> a-c=7n
   c can’t be 0
   so possible combinations-
   8,1(you can also consider n=0 ->a=c)
   and 9,2 ->numbers- 952,259,861,168(palindromes-707,77,868,777)

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2. 48,84
   I believe the above 2 answers are not appropriate because,
   the question says “if digits of X are reversed then we
   obtain NEW number say Y”. i.e., The digits arent Palindrome.

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3. 77

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