Post a New Question

Algebra

posted by .

Consider all 2 digit numbers N such that the last 2 digits of N^2 are N itself. What is the sum of all these 2 digit numbers?

  • Algebra -

    the answer is 76

  • Algebra -

    sorry the answer should be 101

    I do like this:
    first consider the possible last digit of the number, then you have 0,1,5,6

    Let N be ab

    For number end with 0,
    the last two digits of N will be 00
    no numbers can be formed as 00 is not a
    2 digit numbers

    For number end with 1,
    it must satisfy the conditions:
    last digit of 2a=a
    no numbers can be formed

    For number end with 5,
    it must satisfy the conditions:
    last digit of 10a+2=a
    the number 25 can be formed

    For number end with ,
    it must satisfy the conditions:
    last digit of 12a+3=a
    the number 76 can be formed

    Sum of N=76+25=101

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. MATH Trouble

    I have no idea what this problem means: For how many two-digit numbers if the ones digit larger than the tens-digit?
  2. math

    You have 2 digits, 2 numbers, reverse digits and 54 if the difference and the sum of all is 10 I'm not clear what you're asking, could you clarify what the conditions are for us please?
  3. math

    I am a 4-didit number. All my digits are odd numbers and each digit is different. The sum of the tensdigit and hundreds digit is 6. All 4 digits add to 16. Who am I?
  4. Maths

    What are 3 5-digit numbers that have the sum of their digits equal?
  5. Math. Explain

    From the digits 1, 2, 3, and 4, how many positive integers are less than 100,000?
  6. math

    Consider all three-digit numbers that are greater than the sum of the squares of their digits by exactly 543. What are the last three digits of the sum of these numbers?
  7. Algebra

    Consider all three-digit numbers that are greater than the sum of the squares of their digits by exactly 543. What are the last three digits of the sum of these numbers?
  8. Algebra

    Let S(N) denote the digit sum of the integer N. Let M denote the maximum value of N/S(N), where N is a 3-digit number. How many 3-digit numbers N satisfy N/S(N)=M?
  9. maths

    Find the sum of all 3-digit positive numbers N that satisfy the condition that the digit sum of N is 3 times the digit sum of N+3. Details and assumptions The digit sum of a number is the sum of all its digits. For example, 1123 has …
  10. math

    Consider all three-digit numbers that are greater than the sum of the squares of their digits by exactly 543. What are the last three digits of the sum of these numbers?

More Similar Questions

Post a New Question