<p>p.607
19.how many 3 digit palindrome are there.</p>
<p>19
20
100
810
how did u find it</p>
<p>The first and third number are the same, and the second one can be anything.</p>
<p>The only constraint on the first/third number is that it cannot be equal to zero, or else it would not be a three digit number. So there are 9 possibilities (1 through 9).</p>
<p>There are no constraints on the second number. So there are 10 possibilities.</p>
<p>How many combinations are there? 9 x 10 = 90. The answer is C.</p>
<p>You forgot to list THE answer that is 90. </p>
<p>How many numbers can be "in the middle" of three digits palindrome?
Everyone of 0 to 9 ... so that is 10 numbers.</p>
<p>How many can be on the sides?
O is not possible -it would become a single digit number-
That leaves us 9 combinations (1x1, 2x2, 3x3, etc.)</p>
<p>So the answer is 9 times 10 or 90. </p>
<p>PS This way you have 111, 121, 131, 141, all the way to 999.</p>
<p>Number of two digit palindromes:
A two digit palindrome would be of the form: AA : there are 9<em>1 = 9 of them
Number of three digit palindromes:
A three palindrome would be of the form: ABA : there are 9</em>10<em>1 = 90 of them
Number of four digit palindromes:
A four digit palindrome would be of the form: ABBA : there are 9</em>10<em>1</em>1 = 90 of them
Number of five digit palindromes:
A five digit palindrome would be of the form: ABCBA : there are 9<em>10</em>10<em>1</em>1 = 900 of them</p>
<p>wow, i am soo lost. lol. What is a palindrome? and is that going to be on Sat I or SAT II?</p>
<p>
[quote]
What is a palindrome?
[/quote]
</p>
<p>Your dictionary can answer the question for you. If you don't know how to use one, you're going to have definite problems with the SAT.</p>
<p>A palindrome is a number that reads the same forward as it does backward, such as 11, 212, 333, 4664, etc.</p>