posted by .

A pair of emirps consists of two prime numbers such that reversing the digits of one number gives the other. How many pairs of two-digit emirps exist such that each number in the pair is greater than 11?

  • algebra -

    The list of prime numbers between 11 and 100 are:

    11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

    So try them one at a time, say
    number reversed
    11 11 OK
    13 31 OK
    17 71 OK
    19 91 is composite [pair rejected]
    23 32 [rejected]
    97 79 OK

    So you'll get a list in no time.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Number Sentence

    In a 4-digit number, the two greatest place-value digits are 2. The sum of the ones and tens digits is 14. What numbers are possible?
  2. 8th Grade Algebra

    These are extra credit questions, and I just want to know how to solve them. 1) The sum of two-digits of a two digit number is 14. If the number represented by reversing the digits is subtracted from the original number, the result …
  3. algebra

    please explaing reversing the digits. Find the product of 2 two digit numbers and reverse the digits and find the product. The products are the same. Does this happen with any pair of two-digit numbers?
  4. Algebra

    Need help plz. Don't really get this "reversing the digits" What is this really called in math language?
  5. Math

    Find all two-digit numbers such that reversing the digits results in another two-digit number that is 75% larger than the original number.

    there are two prime numbers between 100 and 199 such that the ten digits is a prime number, the ones digit is a prime number and the tens and ones digits taken together are a 2 digit prime number. find the sum of these 2 prime number.
  7. math

    The Twin Prime Conjecture, which has not been proven, argues that there are infinitely many pairs of primes of the form n and n+2. Such a pair is called a prime pair. Some examples of prime pairs are 5 and 7, 17 and 19, and 29 and …
  8. math

    A two digit number is such that two times the tens digit is three less than thrice the units digit and four times the number is 99 greater than the number obtained by reversing the digits. Find the number.
  9. math

    1)a number of two digits is such that the digits is 11 and the number is 27 greater than the number obtained by reversing the digits. a)Find the number b)State the advantages of the mean as an average 2) use logarithm tables to evaluate …
  10. algebra

    A positive two-digit number is such that the product of the digits is 24.When the digits are reversed the number formed is greater than the original number by 18.Find the number.

More Similar Questions