If \(a\) and \(b\) are distinct positive integers, what is the units digit of \(2^a\cdot 8^b\cdot 4^{a+b}?\)

This topic has expert replies
Moderator
Posts: 2058
Joined: Sun Oct 29, 2017 4:24 am
Thanked: 1 times
Followed by:5 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

If \(a\) and \(b\) are distinct positive integers, what is the units digit of \(2^a\cdot 8^b\cdot 4^{a+b}?\)

(1) \(b = 24\) and \(a < 24.\)
(2) The greatest common factor of \(a\) and \(b\) is \(12.\)

Answer: B

Source: Manhattan GMAT
Source: — Data Sufficiency |