What is the value of n in the equation - 25 + 19 + n = S ?

Question

What is the value of n in the equation: - 25 + 19 + n = s ?

(1) s = 2
(2) n/s = 4

Bunuel · Answer

SOLUTION

What is the value of n in the equation - 25 + 19 + n = s ?

(1) s = 2 --> - 25 + 19 + n = 2. We have a linear equation with one unknown, hence we can solve for it. Sufficient. 
(2) n/s = 4 --> s=n/4 --> - 25 + 19 + n = n/4. We have a linear equation with one unknown, hence we can solve for it. Sufficient.

Answer: D.

SOURH7WK · Answer

St 1: Sufficient: Substitute S=2 in 25+19+n=2, Value of n can be found out from this linear equation.
St 2: Sufficient: Substitute s=n/4 in 25+19+n=n/4, Value of n can be found out from this linear equation.

Hence Answer D

fameatop · Answer

Reducing Stem we get 
n = s + 6
1) s=2--> n=8 ---> Sufficient
2) s=n/4 --->Sufficient

Answer D

aditi1903 · Answer

IMO D..
each statement alone is sufficient

thevenus · Answer

What is the value of n in the equation - 25 + 19 + n = s ?

If we have s known then, we can easily find n.

(1) s = 2--------sufficient
(2) n/s = 4 
=> s=n/4------sufficient

Answer : D

Carcass · Answer

D straight Bunuel but could someone think about n/s=4 that n and s can be both positive or negative ?? 16/4 = 4 or -16/-4 = 4 so is not safely to cross multiply  S  ?? or this concern regards questions in which < or > are involved ??'

Thanks

Bunuel · Answer

You should be concerned about the signs only with  inequalities . For equations you can safely cross-multiply.

subirh · Answer

1)n-6=2 .. sufficient
2)n/4=s or,n-6=n/4 -- sufficient. so answer is D

chekitsch · Answer

hello, for statement (2), what if

n=4 and s=1

then -25 + 19 + 4 = -2
but s=1 NOT GOOD

also consider if n=8 and s=2

then -25 + 19 + 8 = 2
and s = 2 GOOD

since it is possible to pick different sets of numbers that yield conflicting answers, shouldn't this statement alone be insufficient? (refer to OG13 DS#41 for comparison)

Bunuel · Answer

n=4 and s=1 do not satisfy - 25+19+n=s.

We have two equations: - 25+19+n=s and n/s=4. Solving gives n=8 and s=2.

selfishmofo · Answer

For the second statement: I know I should stop after knowing that it's a linear-with one unknown, I'm rusty on my math, how does this become

I get this, N/S=4
 S=4N (multiply each side)
 (lost in this step) I did the following
 N=S+6 
 N=4N+6
 -3N=6
 3 3
 N=-2, (should be positive)

Not sure how I got a negative, I guessed correctly, the second time i worked the problem. I'm not sure how the MGMAT guide states that the number becomes S=1/4N, maybe so it's not negative, it's placed with a fraction? Can someone refresh me with that concept. thanks.

Bunuel · Answer

Not sure I understand everything in your post but n/s = 4 means n = 4s (multiply both sides by s) not s = 4n.

Hope it helps.

selfishmofo · Answer

I'm not sure how the MGMAT guide states that the number becomes S=1/4N, maybe so it's not negative, it's placed with a fraction? Can someone refresh me with that concept. Thank you for the other concept, I missed that small detail in trying to explain the problem.

Bunuel · Answer

n = 4s  -->  s = \frac{n}{4}  or  \frac{1}{4}*n  (it's not  \frac{1}{4n} ).

BrentGMATPrepNow · Answer

Given : -25 + 19 + n = s  
Simplify: -6 + n = s 
Add 6 to both sides to get:  n = s + 6

Target question :    What is the value of n?

Statement 1 : s = 2  
We already know that  n = s + 6 
Replace s with 2 to get:  n = 2 + 6 = 8 
The answer to the target question is  n = 8 
Since we can answer the  target question  with certainty, statement 1 is SUFFICIENT

Statement 2 : n/s = 4  
Multiply both sides by s to get: n = 4s
Divide both sides by 4 to get: n/4 = s

We already know that  n = s + 6 
Replace s with s with n/4 to get:  n = n/4 + 6 
Multiply both sides by 4 to get: 4n = n + 24
Subtract n from both sides to get: 3n = 24
Solve, n = 8
The answer to the target question is  n = 8 
Since we can answer the  target question  with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent

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What is the value of n in the equation - 25 + 19 + n = S ?

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What is the value of n in the equation - 25 + 19 + n = S ?

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