I have been trying this problem for awhile now but i cant get it. Can someone please help?
Hannah is instructed to write down a positive, 4-digit integer. What is the probability it is an even palindrome (a number that reads the same forward and backward)? Express your answer as a common fraction.
+128407 Even plaindromes
Starts with Ends with
2 2
4 4
6 6
8 8
We have 10 choices for the middle two numbers in each case = 40 possibiliities
We have 90 4 digit palindromes (the other 50 come from starting and ending the number with 1,3,5,7, or 9....and for each of these we have 10 possibiliites)
So....the probability of an even palindrome = 40 / 90 = 4 / 9
+118608 CPhill has found the probability that it is an even palidrome given that it is a palindrome.
I do think think this is quite what the question is asking.
I think it wants the probability that it is a 4 digit even palidrone given that it is a 4 digit number.
The number of 4 digit numbers is 9*10*10*10 = 9000
The answer I believe is
4/900
