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    Study homework help Dagmara_4871

    This maths question is really bugging me. In my Active Maths Book 1 pg 116 question 13, there is a question on palindromic numbers. I understand the term palindromic and got my first answer to part (i) which asked me the amount of 3 digit palindromic number ...my answer is 90 ...now it asks me to find the number of palindromic numbers between 10 to the power of 6 and 10 to the power of 7.

    I know from the back of the book that the answer is supposed to be 9000 but when i try the question i get a different answer. Andyone know how to do it?

    1. avatar image

      michaels

      (i) 9x10x1 = 90

      (ii)10^6 = 1000000

      10^7 = 10000000

      therefore 9 x 10 x 10 x 10 x 1 x 1 x 1 = 9000

    2. avatar image

      michaels

      Hope that helps

    3. avatar image

      smcshane

      Michaels is correct,

      10^6 is a seven digit number and 10^7 is an eight digit number so all the numbers in between are 7 digit numbers.

      9 choices (1-9) for the first digit, which means 1 for the seventh (as it has to be the same)

      10 choices (0-9) for the second digit, which means 1 for the sixth (as it as to be the same)

      10 choices (0-9) for the third digit, which means 1 for the fifth (as it as to be the same)

      10 choices (0-9) for the fourth digit.

      So thats where you get

      9 x 10 x 10 x 10 x 1 x 1 x 1 = 9,000

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      Me

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