GMAT Question for the math whizzes on AF. How do you solve a question like this? A palindrome is a number that reads the same forward and backward, such as 121. How many odd, 4-digit numbers are palindromes? 40, 45, 50,90, or 2500?
i’m guessing 50 5 odd numbers to start/end x 10 possible numbers to go in the middle
50
Beat me to it, agree with 50 for said reasoning
mar350 Wrote: ------------------------------------------------------- > i’m guessing 50 > > 5 odd numbers to start/end x 10 possible numbers > to go in the middle Seems like sound logic, but I’m not a math whiz.
Is this a math question?
It’s more of a logical thinking question than a math question. Just think through it step by step. 1. You know that the first and last digits are the same for palindrome numbers, so all such odd numbers are 1xx1, 3xx3, 5xx5, 7xx7, or 9xx9. 2. The two middle digits must be the same, and there are ten such combinations. Therefore, the answer is 50. 90 is probably there to trap people who forget that it only wants odd numbers. I’m not sure if there is a fixed way to do this sort of question, but practice questions will probably help you get the general rhythm of what they will ask you in the real test.
Not really. I was just making it a lot harder than it should have been. Thanks!