Search This Blog

Loading...

Maths Logic Riddle

Maths Logic Riddle - 10 April

It can be easily calculated that the digits 0 to 9 can be arranged into 3628800 distinct ten digit numbers.

But i also knowns how many of these numbers are prime.

Do you ?

For Solution : Click Here

15 comments:

  1. yes, i know ,it is zero;
    bcoz :-in permutations of 0 to 9 digits;
    sum of digit is 0+1+2..+9=(9*10)/2=45;
    which is divisible by 3,hence the entire number;
    hence no number can be prime......

    ReplyDelete
    Replies
    1. I think you are born genius.............
      your ans is absolutely correct

      Delete
  2. Logic:
    0
    The sum of numbers is 45, which is divided into 9. It means that all this numbers has at most 4 divisors: 1, itself, 3 and 9.

    ReplyDelete
    Replies
    1. Think you mean at least, not at most. Otherwise absolutely correct :)

      Delete
    2. Logic:
      Yes you are right :)

      Delete
  3. This comment has been removed by the author.

    ReplyDelete
  4. The number of 10-digit numbers using the digits is only 3,265,920 NOT 3,628,800 because numbers starting with a zero are not 10-digit numbers..
    However there are no primes....

    ReplyDelete
    Replies
    1. i agree with you.. it should be 9*9! and not 10!

      Delete
  5. Tricky...
    None of them is prime...

    ReplyDelete
  6. Hey am i missing something here, won't the number of distinct 10 digit numbers be 9*10^9. Nowhere question mentions that the digits need to be non-repetitive. And in that case the answer to number of primes might also not be zero.

    ReplyDelete
  7. I did not go to school in english speaking countries. So, I'm not good with academic english words. Please explain to me what are the characteristics of "Prime" numbers? Thank you.

    ReplyDelete
  8. I did not go to school in english speaking countries. So, I'm not good with academic english words. Please explain to me what are the characteristics of "Prime" numbers? Thank you.

    ReplyDelete