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.
Which of the following CANNOT
[#permalink]
09 May 2015, 11:35
09 May 2015, 11:35
Expert Reply
00:00
Question Stats:
56% (01:07) correct
43% (01:10) wrong based on 44 sessions
Hide Show timer Statistics
Which of the following CANNOT be the sum of two integers that have a product of 30?
(A) 31
(B) 17
(C) –11
(D) –13
(E) –21
Kudos for the right answer and explanation
(A) 31
(B) 17
(C) –11
(D) –13
(E) –21
Kudos for the right answer and explanation
Re: GRE Math Challenge #87- Which of the following CANNOT
[#permalink]
18 Dec 2017, 00:45
18 Dec 2017, 00:45
1
sandy wrote:
Which of the following CANNOT be the sum of two integers that have a product of 30?
(A) 31
(B) 17
(C) –11
(D) –13
(E) –21
(A) 31
(B) 17
(C) –11
(D) –13
(E) –21
Here 30 can be written as-
5 * 6
10 * 3
15 * 2
The sum of these integeres are
5 +6 = 11
10 + 3 =13
15 + 2 = 17
But sum of these can also be negative, since negative * negative = postive i. e
-5 + (-6) = -11 and -5 * -6 = 30
-10 + (-3)= -13 and -10 * -3 = 30
-15 + (-2)= -17 and -15 * -2 = 30.
Thus only -21 donot fit into this and hence is the answer
Re: GRE Math Challenge #87- Which of the following CANNOT
[#permalink]
18 Dec 2017, 02:33
18 Dec 2017, 02:33
1
We can list the factors of 30.
30 * 1 = 30 SUM = 31
15 * 2 = 30 SUM = 17
10 * 3 = 30 SUM = 13
6 * 5 = 30 SUM = 11
Remember that two negative numbers give us a positive number. So we shoukd consider their negatives.
The only answer that does not show up us D.
30 * 1 = 30 SUM = 31
15 * 2 = 30 SUM = 17
10 * 3 = 30 SUM = 13
6 * 5 = 30 SUM = 11
Remember that two negative numbers give us a positive number. So we shoukd consider their negatives.
The only answer that does not show up us D.
