GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 22 Aug 2019, 00:59 ### 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
Your Progress

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. ### Request Expert Reply # Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Math Expert V
Joined: 02 Sep 2009
Posts: 57221
Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what  [#permalink]

### Show Tags 00:00

Difficulty:   15% (low)

Question Stats: 77% (01:26) correct 23% (01:51) wrong based on 100 sessions

### HideShow timer Statistics

Given that $$m^2 - 2m -15 = 0$$ and $$n^2 - 3n - 10 = 0$$, where m ≠ n, what is the product of m and n?

(A) -15
(B) -10
(C) -6
(D) 6
(E) 15

_________________
Senior PS Moderator V
Joined: 26 Feb 2016
Posts: 3355
Location: India
GPA: 3.12
Re: Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what  [#permalink]

### Show Tags

Bunuel wrote:
Given that $$m^2 - 2m -15 = 0$$ and $$n^2 - 3n - 10 = 0$$, where m ≠ n, what is the product of m and n?

(A) -15
(B) -10
(C) -6
(D) 6
(E) 15

Factorizing the two equations
$$m^2 - 2m -15 = 0$$ -> $$m^2 - 5m + 3n -15 = 0$$ -> $$(m-5)(m+3) = 0$$ -> $$m = 5 or -3$$
$$n^2 - 3n - 10 = 0$$ -> $$n^2 - 5n + 2n - 10 = 0$$ -> $$(n-5)(n+2) = 0$$ -> $$n = 5 or -2$$

Therefore, the product of m and n such that m≠n is (-3)(-2) = 6(Option D)
_________________
You've got what it takes, but it will take everything you've got
Intern  B
Joined: 07 Jul 2017
Posts: 1
Re: Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what  [#permalink]

### Show Tags

Can answer be -10 and -15 also? the question stated that m ≠ n , doesn’t that means m = 5, n = -2 or m = -3, n = 5 also possible?
Director  P
Joined: 02 Oct 2017
Posts: 726
Re: Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what  [#permalink]

### Show Tags

After solving equation we get
m=5 or -3
n=5 or -2

It is written that m is not equal to n
Then options 6,-10 and -15 also fulfill the criteria..
considering choosing the answer answer should be 6
But otherwise options in this question are not correct.

Posted from my mobile device
_________________
Give kudos if you like the post
VP  D
Joined: 31 Oct 2013
Posts: 1429
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what  [#permalink]

### Show Tags

Bunuel wrote:
Given that $$m^2 - 2m -15 = 0$$ and $$n^2 - 3n - 10 = 0$$, where m ≠ n, what is the product of m and n?

(A) -15
(B) -10
(C) -6
(D) 6
(E) 15

It's given that m is not equal to n.

$$m^2-2m-15=0$$

$$m^2 - 5m + 3m - 15 =0$$

m(m-5) + 3(m-5) = 0

(m-5)(m+3)=0

So, the value of m = 5 or -3.

$$n^2 - 3n - 10 = 0$$

$$n^2 - 5n + 2n -10=0$$

(n-5) (n+2) = 0.

So the value of n = 5 or -2

Note: we know m and n can't be equal as per the direction of the question.

Thus the value of mn will be (-3) (-2) = 6

The correct answer is D.
Director  V
Joined: 27 May 2012
Posts: 838
Re: Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what  [#permalink]

### Show Tags

linggling wrote:
Can answer be -10 and -15 also? the question stated that m ≠ n , doesn’t that means m = 5, n = -2 or m = -3, n = 5 also possible?

Absolutely you are correct , on solving for m we get m =5 or m=-3
on solving for n we get n =5 or n =-2
now we know that m $$\neq$$ n , hence m and n cannot both be 5, the following pairs of (m n) are possible
(-3 5) (-3,-2) (5, -2) hence product of m and n can be -15, 6, -10 all of these are present in the options .

Please let me know if I am missing anything. Thanks.
_________________
- Stne Re: Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what   [#permalink] 23 Aug 2018, 05:27
Display posts from previous: Sort by

# Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m ≠ n, what

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

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

#### MBA Resources  