Brent@GMATPrepNow wrote:If y is 4 greater than one-fourth of x, and x ≠0, what is the ratio of y to x in terms of x?
A) (x² + 16x)/4
B) (4x + 16)/x
C) (x + 16)/4x
D) (4x + 1)/x
E) (x + 16)/x
Answer:
C
Difficulty level: 550-600
Source:
www.gmatprepnow.com
*I'll post a solution in 2 days
The solutions above demonstrate an algebraic approach.
We can also solve the question using the INPUT-OUTPUT approach.
Let's find values for x and y that satisfy the given information (y is 4 greater than one-fourth of x)
A nice pair of values is
x = 4 and y = 5
When we use these values, the answer to our question ("what is the ratio of y to x in terms of x? ") is
5/4
In other words, when we INPUT
x = 4, the OUTPUT is
4/5
So, now take each answer choice, replace x with
4 and see which one yields an OUTPUT of
5/4
A) [
4² + 16(
4)]/4 =
20. No good. We want an output of
5/4. ELIMINATE.
B) [4(
4) + 16]/
4 =
8. No good. We want an output of
5/4. ELIMINATE.
C) (
4 + 16)/4(
4) = 20/16 =
5/4. Great! KEEP
D) [4(
4) + 1]/
4 =
17/4. No good. We want an output of
5/4. ELIMINATE.
E) (
4 + 16)/
4 =
5. No good. We want an output of
5/4. ELIMINATE.
Answer: C
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
