Last visit was: 08 Aug 2024, 17:24 It is currently 08 Aug 2024, 17:24
Toolkit
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

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

Track

every week, we’ll send you an estimated GMAT 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.

# In a sequence of numbers, if the first number is a positive integer an

SORT BY:
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 94837
Own Kudos [?]: 647989 [26]
Given Kudos: 86892
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6804
Own Kudos [?]: 30981 [6]
Given Kudos: 799
General Discussion
Senior Moderator - Masters Forum
Joined: 19 Jan 2020
Posts: 3128
Own Kudos [?]: 2824 [2]
Given Kudos: 1511
Location: India
GPA: 4
WE:Analyst (Internet and New Media)
Intern
Joined: 13 Jun 2019
Posts: 39
Own Kudos [?]: 8 [3]
Given Kudos: 5
Re: In a sequence of numbers, if the first number is a positive integer an [#permalink]
3
Kudos
The wordings are confusing here. As per the question stem, it is written that In a sequence of numbers, if the first number is a positive integer and if each number thereafter is the least prime number greater than the preceding number.

from this we can infer that each number is greater than its preceding number by 2, as 2 is the least prime number.
Director
Joined: 09 Jan 2020
Posts: 953
Own Kudos [?]: 236 [0]
Given Kudos: 432
Location: United States
In a sequence of numbers, if the first number is a positive integer an [#permalink]
Bunuel wrote:
In a sequence of numbers, if the first number is a positive integer and if each number thereafter is the least prime number greater than the preceding number, what is the value of the fifth number in the sequence?

(1) The sum of the first two numbers in the sequence is equal to the third number in the sequence.
(2) The sum of the third and fourth numbers in the sequence is 8.

DS20395

(1) If the first two numbers in the sequence is equal to the third number:

$$2, 3, 5, 7, 11$$
or
$$1, 2, 3, 5, 7$$

The fifth number could be 7 or 11. INSUFFICIENT.

(2) If the sum of the 3rd and 4th number is 8, we have:

$$1, 2, 3, 5, 7$$

The fifth number is 7. SUFFICIENT.

RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11518
Own Kudos [?]: 34998 [0]
Given Kudos: 333
Re: In a sequence of numbers, if the first number is a positive integer an [#permalink]
Bunuel wrote:
In a sequence of numbers, if the first number is a positive integer and if each number thereafter is the least prime number greater than the preceding number, what is the value of the fifth number in the sequence?

(1) The sum of the first two numbers in the sequence is equal to the third number in the sequence.
(2) The sum of the third and fourth numbers in the sequence is 8.

DS20395

So first number is a positive integer, and numbers thereafter are primes. So we can say for sure that all numbers after 2nd number will be odd for sure.=> 1,2,3,5,...
Although it is possible that all are odd. => 9,11,13,17...
We are looking for 5th number => If we know any number in the sequence we can find the answer

(1) The sum of the first two numbers in the sequence is equal to the third number in the sequence.
The third number will always be Odd, so the sum of first and second number is ODD => Means one of the two is odd and other even.
There can be many possibilities of this scenario.
1,2,3,5,7...
2,3,5,7,11...
4,7,11,13,17...
4,13,17,19,23...

(2) The sum of the third and fourth numbers in the sequence is 8.
Since the sum is even, both the numbers are odd and prime ofcourse.
In how many ways can we split 8 into TWO primes.
Only one 8=3+5
So the fifth number will be the next prime after 5, that is 7.
Not important but the sequence here will be 1,2,3,5,7,11...
Suff

B
Intern
Joined: 03 Jul 2020
Posts: 18
Own Kudos [?]: 14 [1]
Given Kudos: 9
Re: In a sequence of numbers, if the first number is a positive integer an [#permalink]
1
Kudos
The wordings are confusing here. As per the question stem, it is written that In a sequence of numbers, if the first number is a positive integer and if each number thereafter is the least prime number greater than the preceding number.

from this we can infer that each number is greater than its preceding number by 2, as 2 is the least prime number.

Agreed, wording, threw me off as well.
Non-Human User
Joined: 09 Sep 2013
Posts: 34303
Own Kudos [?]: 859 [0]
Given Kudos: 0
Re: In a sequence of numbers, if the first number is a positive integer an [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT 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.
Re: In a sequence of numbers, if the first number is a positive integer an [#permalink]
Moderator:
Math Expert
94837 posts