Last visit was: 19 Jul 2024, 22:48 It is currently 19 Jul 2024, 22:48

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Own Kudos [?]: 360 [1]
Given Kudos: 64
GRE 1: Q160 V152
Send PM
Retired Moderator
Joined: 02 Dec 2020
Posts: 1833
Own Kudos [?]: 2133 [1]
Given Kudos: 140
GRE 1: Q168 V157

GRE 2: Q167 V161
Send PM
Intern
Intern
Joined: 12 Jul 2021
Posts: 4
Own Kudos [?]: 0 [0]
Given Kudos: 2
Send PM
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Own Kudos [?]: 360 [1]
Given Kudos: 64
GRE 1: Q160 V152
Send PM
Re: How many integers between 13 [#permalink]
1
rx10 wrote:
Range : 13 to 217

A no. with remainder \(4\) after divided by \(7\)

Nos will be 18, 25, 32, ... , 214

In an arithmetic series : T_n \(= a + (n-1)d\)
where,
T_n = \(n^{th}\) term
\(a =\) first term
\(d =\) common difference

\(214 = 18 + (n-1)7\)

\(n = 29\)

Answer C


Accepted. Your solution may be a bit cumbersome, if I enter additional operation, say divided by 8 with the remainder 3. Then we are looking for two sets of integers with a common subset.

My take on this question is universal and follows
\(7x + 4 =< 217\), where \(x\) is integer and \(4\) is a remainder.
\(7x =< 213\), and \(x =< 30\) \(3/7\) not including the case with \(x=0\). Hence 31 integers are between 0 ... 217, and reducing the number of integers by 2 for \(x = {0, 1}\) result in \(7x + 4\) such as \(7*0+4=4\) and \(7*1+4=11\). Answer is \(31-2=29\) integers. As I said with additional operation and more remainders we are looking into a common subset and need to simplify the solution, IMH :|
Prep Club for GRE Bot
[#permalink]
Moderators:
GRE Instructor
49 posts
GRE Forum Moderator
26 posts
Moderator
1091 posts
GRE Instructor
218 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne