Summer Clouds moderators
15/09/2017 at 08:55-
The general forms of the satisfied palindromes are \(\overline{bb},\overline{cdc},\overline{effe}\)
The number of 2-digit palindromes is : (99 - 11) : 11 + 1 = 9
There are 9 choices to choose c and 10 choices to choose d, so the number of 3-digit palindromes is : 9 x 10 = 90
The only 4-digit palindrome is 1001
So, the answer is : 9 + 90 + 1 = 100 (palindromes)
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→இے๖ۣۜBoy™†hïếuGîa 16/09/2017 at 13:38The general forms of the satisfied palindromes are ¯¯¯¯¯bb,¯¯¯¯¯¯¯¯cdc,¯¯¯¯¯¯¯¯¯¯¯effebb¯,cdc¯,effe¯
The number of 2-digit palindromes is : (99 - 11) : 11 + 1 = 9
There are 9 choices to choose c and 10 choices to choose d, so the number of 3-digit palindromes is : 9 x 10 = 90
The only 4-digit palindrome is 1001
So, the answer is : 9 + 90 + 1 = 100
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Math You Like 16/09/2017 at 16:06The general forms of the satisfied palindromes are
The number of 2-digit palindromes is : (99 - 11) : 11 + 1 = 9
There are 9 choices to choose c and 10 choices to choose d, so the number of 3-digit palindromes is : 9 x 10 = 90
The only 4-digit palindrome is 1001
So, the answer is : 9 + 90 + 1 = 100 (palindromes)