A palindrome is a number that reads the same forward and backward.

900?

- - - - - 5 places to filled. 1 blank can be filled in 9 ways.(1-9) last blank in 1 way as it has to be the same number as the 1 blanck. 2 blank can be filled in 10 ways (0-9). similarly 4 blank can be filled in 1 way only. lastly the 3 blank can also be filled in 10 ways
so 9*10*10=900

Hey kunalcvrce,

I have one question.

Can A be 0??

Regards,
Ashutosh

Number is of the form abcde
a can be filled in 9 ways (1-9)
b can be filled in 10 ways (0-9)
c can be filled in 10 ways (0-9)
d=b, so 1 way
e=a, so 1 way
total = 9*10*10*1*1 = 900

Hello everyone,

Thanks for participation.

We have posted the official answer to the question.

Regards,
Ashutosh
e-GMAT

EgmatQuantExpert , a couple of items are inconsistent.

It appears that Question #2:
1) ought to list 0-9 as the digits that are available in both topic threads (the solution prompt needs to be edited to match original);
2) ought to have a calculation error corrected.

Issues
(1) 0-9 or 1-9?
In the original prompt for Q #2, the available digits are integers 0-9. In the solution prompt (please see highlights above), both (1-9) and (0-9) are listed.

The original prompt for Question #2 that lists 0-9 is HERE
(2) the second post on Q#2 solution has a calculation error, although the OA is listed correctly.

(9 * 10 * 10 * 1 * 1) = 900, not 729.

It appears that Questions #1 and #2 got mixed up. The answer to Question 1 HERE, (answer is HERE) is 729.
In Question #1, the digits are limited to 1-9.

I think Q#2
-- needs to state that integers are 0-9 in all posts and
-- needs to have the written answer changed to 900

Would you please correct the inconsistencies?

EgmatQuantExpert :

quoting your line
Thus, way to form a 5-digit palindrome number= 9 * 10 * 10 *1 *1= 729.
it should be 900 not 729..

Hey Archit3110,
We have made the changes.
Thanks

@experts in this question repetition of digits is allowed. are we to assume if the question doesn't mention specifically that repetition isn't allowed then it is?

If not specifically mentioned, we will consider ‘with replacement ‘

May I ask if the possibility of 11111 22222 etc. Is not considered

Posted from my mobile device

9*10*10*1*1 will also give all numbers with repeated digits.

10 in 9*10*10*1*1, means that the second digit can be any, so it can be the same as the first and another 10 in 9*10*10*1*1, means that the third digit can be any, so it can be the same as the first and the second.

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