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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what Updated on: 25 Mar 2026, 09:06
Originally posted by Bunuel on 10 Apr 2018, 22:18.
Last edited by Bunuel on 25 Mar 2026, 09:06, edited 1 time in total.
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80% (01:34) correct 20% (02:12) wrong based on 296 sessions

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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

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D
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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what 10 Apr 2018, 23:41
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Bunuel
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
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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)
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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what 11 Apr 2018, 02:13
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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?
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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what 21 Apr 2018, 06:17
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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.

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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what 21 Apr 2018, 17:26
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Bunuel
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
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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.
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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what 23 Aug 2018, 05:27
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linggling
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?
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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.
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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what 15 Mar 2026, 08:05
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On solving 1 equation we get m =5 or m=-3
on solving another for n we get n =5 or n =-2
now we know that m 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 . Then why are we picking only 6 as the answer why not other options let me know if I am missing something conceptually?
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Given that m^2 - 2m -15 = 0 and n^2 - 3n - 10 = 0, where m n, what 25 Mar 2026, 08:15
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No, u r not. I think it is just one of the questions with bad answer choices
I too wasted a lot of time thinking of possible ways of eliminating the other correct choices

NupurNeha123
On solving 1 equation we get m =5 or m=-3
on solving another for n we get n =5 or n =-2
now we know that m 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 . Then why are we picking only 6 as the answer why not other options let me know if I am missing something conceptually?
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