y = kx + 3
In the equation above, k is a constant. If y = 17 when x = 2, what is the value of y when x = 4 ?
A) 34
B) 31
C) 14
D) 11
E) 7
OA: B
In the equation above, k is a constant.
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Let's find the value of kboomgoesthegmat wrote:y = kx + 3
In the equation above, k is a constant. If y = 17 when x = 2, what is the value of y when x = 4 ?
A) 34
B) 31
C) 14
D) 11
E) 7
OA: B
We're told that y = 17 when x = 2 is one solution to the equation y = kx + 3
This means that 17 = k(2) + 3
Simplify: 17 = 2k + 3
So, 14 = 2k
We get: k = 7
So, the equation is y = 7x + 3
When x = 4, we get y = 7(4) + 3
So, y = 28 + 3 = 31
Answer: B
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Hi All,
For most Test Takers, working through the basic Arithmetic would arguably be the fastest and easiest approach (as Brent has shown). If you ever get 'stuck' on a question though, it's important to remember that GMAT questions are almost always based around patterns.
With this question, we're told that Y=17 when X=2. With the given equation (Y = KX + 3), you can see that Y is '3 more' than a multiple of 2. We're asked for the value of Y that occurs when X=4, so Y will certainly get bigger.... So which answer is 3 more than a multiple of 4 and is bigger than 17? There's only one...
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
For most Test Takers, working through the basic Arithmetic would arguably be the fastest and easiest approach (as Brent has shown). If you ever get 'stuck' on a question though, it's important to remember that GMAT questions are almost always based around patterns.
With this question, we're told that Y=17 when X=2. With the given equation (Y = KX + 3), you can see that Y is '3 more' than a multiple of 2. We're asked for the value of Y that occurs when X=4, so Y will certainly get bigger.... So which answer is 3 more than a multiple of 4 and is bigger than 17? There's only one...
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
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- Jeff@TargetTestPrep
- GMAT Instructor
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We are given the equation y = kx + 3, where k is a constant.boomgoesthegmat wrote:y = kx + 3
In the equation above, k is a constant. If y = 17 when x = 2, what is the value of y when x = 4 ?
A) 34
B) 31
C) 14
D) 11
E) 7
We are also given that y = 17 when x = 2, so we can plug these values into the equation to first determine a value for the constant k.
y = kx + 3
17 = 2k + 3
14 = 2k
k = 7
We now know the constant value of k and so we can determine the value of y when x = 4:
y = kx + 3
y = (7)(4) + 3
y = 28 + 3
y = 31
Answer: B
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