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Maths Number Riddle

Maths Number Riddle - 22 April

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number ?

For Solution : Click Here


  1. it is not possible ,bcoz say,number is x.....z of unknown length x and z are first and last digit respectively double of z should produce ultimatly x digit and double of x should produce either z or z-1 as digit a because after multiplying there may be a carry now we have to find such (z,x) unit_digit(2*z)=x; and unit_digit(2*x)=z or z-1
    for z=3,it seems to be true and no. is 6......3 i.e 6z3 where z is a no which on double will give one carry and reverse of z;which is forget about carry of number this problem is again reduced to above problem by number of iteration we can see no solution exists

  2. 6z3; case there is a carry so it is obeviosly rejected as z string is not 1

  3. How did you calculate the answer?