BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

do not contain the digits 3 or 6

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

do not contain the digits 3 or 6

by sanju09 » Tue May 24, 2011 1:34 am
How many four-digit numbers are there that do not contain the digits 3 or 6?
(A) 2401
(B) 3584
(C) 4096
(D) 5040
(E) 7200


[spoiler]Source: Eric's collection on BTG


OA B[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 436
Joined: Tue Feb 08, 2011 3:07 am
Thanked: 72 times
Followed by:6 members

by manpsingh87 » Tue May 24, 2011 3:02 am
sanju09 wrote:How many four-digit numbers are there that do not contain the digits 3 or 6?
(A) 2401
(B) 3584
(C) 4096
(D) 5040
(E) 7200


[spoiler]Source: Eric's collection on BTG


OA B[/spoiler]
-,-,-,-; leftmost digit can be filled with any of the seven digits(1,2,4,5,7,8,9) in 7 ways;
and for each of the remaining digit we have 8 ways of filling the spaces by using digits 0,1,2,4,5,7,8,9; hence required no. of ways= 7*8*8*8= 3584 hence B
O Excellence... my search for you is on... you can be far.. but not beyond my reach!
Top
Post new topic Post Reply
• Page 1 of 1