GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
A number that is a palindrome reads the same way forwards an
[#permalink]
22 Apr 2020, 12:40
22 Apr 2020, 12:40
Expert Reply
3
Bookmarks
00:00
Question Stats:
72% (01:16) correct
27% (01:13) wrong based on 18 sessions
Hide Show timer Statistics
A number that is a palindrome reads the same way forwards and backwards. For example, 3113 and 7447 are palindromes. Let n be the product of all 4-digit palindromes. What is the unit’s digit of n?
A. 0
B. 2
C. 4
D. 5
E. 8
A. 0
B. 2
C. 4
D. 5
E. 8
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: A number that is a palindrome reads the same way forwards an
[#permalink]
22 Apr 2020, 12:59
22 Apr 2020, 12:59
1
Carcass wrote:
A number that is a palindrome reads the same way forwards and backwards. For example, 3113 and 7447 are palindromes. Let n be the product of all 4-digit palindromes. What is the unit’s digit of n?
A. 0
B. 2
C. 4
D. 5
E. 8
A. 0
B. 2
C. 4
D. 5
E. 8
There are many 4-digit palindrome numbers. Included among these palindrome numbers are 5005 and 2002 (and many others)
If n = the product of all 4-digit palindrome numbers, ....
...then n = (5005)(2002)(#)(#)(#)(#)(#)(#)....
= (10020010)(#)(#)(#)(#)(#)(#)....
Since 10020010 has units digit 0, we know that the entire product (aka n) will have units digit 0
Answer: A
Cheers,
Brent
Re: A number that is a palindrome reads the same way forwards an
[#permalink]
27 Aug 2021, 23:07
27 Aug 2021, 23:07
Hello from the GRE Prep Club BumpBot!
Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
