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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
GRE Math Challenge #47-A 'Q-group' is defined
[#permalink]
19 Sep 2014, 03:56
19 Sep 2014, 03:56
Expert Reply
00:00
Question Stats:
48% (01:00) correct
51% (01:13) wrong based on 39 sessions
Hide Show timer Statistics
A 'Q-group' is defined as a pair (a,b) where a,b are +ve integers and
b = (90 - a) / 5
After refering to above data, how many different Q-groups of +ve integers are there?
A) 10
B) 15
C) 17
D) 18
E) Infinite.
b = (90 - a) / 5
After refering to above data, how many different Q-groups of +ve integers are there?
A) 10
B) 15
C) 17
D) 18
E) Infinite.
Re: GRE Math Challenge #47-A 'Q-group' is defined
[#permalink]
07 Jun 2019, 08:36
07 Jun 2019, 08:36
1
Can anyone pls explain the above math ?
Regards,
Regards,
Re: GRE Math Challenge #47-A 'Q-group' is defined
[#permalink]
07 Jun 2019, 08:41
07 Jun 2019, 08:41
1
Got it.
b has to be a different positive integer.
as b=(90-a)/5, so, b will be integers only in the cases where a will be the multiples of 5- i.e. from 5 to 85. So, total 17 values. Not a=90, because (90-90)/5 gives no positive integer value for b. So , Total 17 Q-group values .
b has to be a different positive integer.
as b=(90-a)/5, so, b will be integers only in the cases where a will be the multiples of 5- i.e. from 5 to 85. So, total 17 values. Not a=90, because (90-90)/5 gives no positive integer value for b. So , Total 17 Q-group values .
