Forum Home > GMAT > Quantitative > Problem Solving (PS)
Events & Promotions
GMAT 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.
Sep 0810:00 AM PDT
-11:00 AM PDT
Paid vs Free GMAT Resources: "What's Best for You?" This concise guide breaks down the pros and cons of both free and paid study materials, helping you make an informed decision for your GMAT journey.
Sep 1211:00 AM EDT
-12:00 PM EDT
Have you ever wondered how to score a PERFECT 805 on the GMAT? Meet Julia, a banking professional who used the Target Test Prep course to achieve this incredible feat. Julia's story is nothing short of an inspiration.
Sep 1310:00 AM EDT
-11:00 AM EDT
More and more TTP students are earning impressive scores on the GMAT. Now is the perfect time to join the many GMAT students who made the switch to TTP and surpassed their wildest expectations on test day.
Sep 1411:00 AM IST
-01:00 PM IST
Text – Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies, Tackle difficult RC & MSR with confidence, Excel in timed test environment- Sep 15
11:00 AM IST
-01:00 PM IST
Attend this session to evaluate your current skill level, learn process skills, and solve through tough Arithmetic questions.
What is the unit digit of 4387^245*621^72 ?
[#permalink]
04 Jul 2022, 12:45
04 Jul 2022, 12:45
2
Bookmarks
Expert Reply
Show timer
00:00
A
B
C
D
E
Difficulty:
5%
(low)
Question Stats:
84% (00:49) correct
16%
(01:27)
wrong
based on 96
sessions
What is the unit digit of \(4387^{245}*621^{72}\) ?
(A) 1
(B) 2
(C) 5
(D) 7
(E) 8
(A) 1
(B) 2
(C) 5
(D) 7
(E) 8
Re: What is the unit digit of 4387^245*621^72 ?
[#permalink]
04 Jul 2022, 16:10
04 Jul 2022, 16:10
Expert Reply
This question is recurrent in the GMAT official guide books.
Attachments
5ADD57AA-E7AB-462E-8C55-41F21EC297DB.jpeg [ 231.91 KiB | Viewed 2052 times ]
What is the unit digit of 4387^245*621^72 ?
[#permalink]
04 Jul 2022, 16:15
04 Jul 2022, 16:15
1
Bookmarks
Expert Reply
Bunuel wrote:
What is the unit digit of \(4387^{245}*621^{72}\) ?
(A) 1
(B) 2
(C) 5
(D) 7
(E) 8
(A) 1
(B) 2
(C) 5
(D) 7
(E) 8
Units digit of 621^anything is 1, so we can just ignore that part.
\(4387^{245}\)
7^something cycles 7, 9, 3, 1. B, C, and E are out.
Is 245 a multiple of 4? Nope. A is out.
Answer choice D.
