GMATPrepNow wrote:

Moe is 20% taller than Jane. If Moe is x inches tall, which of the following represents Jane's height in inches?

A) 4x/5

B) 5x/6

C) 2x/3

D) 5x/4

E) 6x/5

I created this question to highlight a common misconception that goes something like this:

If Moe is 20% taller then Jane, then Jane must be 20% shorter than Moe. If you have this misconception, then you will

incorrectly choose A as your answer.

For more on this common misconception, read

https://www.gmatprepnow.com/articles/co ... 93-part-iiMoe is 20% taller than Jane.Let J = Jane's height (in inches)

So, 1.2J = Moe's height

Moe is x inches tall.We just learned that 1.2J = Moe's height

So, we can write: 1.2J = x

Since 1.2 = 6/5, we can rewrite the equation as follows: (6/5)J = x

Which of the following represents Jane's height in inches? Solve the equation (6/5)J = x for J

Multiply both sides of the above equation by 5/6 to get: J = (5/6)(x)

Simplify: J = 5x/6

Answer: B

Cheers,

Brent

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Brent Hanneson – Founder of gmatprepnow.com