Math Question

GRE Quant Problem Solving
1

Question states:
w>1
A) 7w-4
B) 2w+5

my thought process:
since w is greater than 1, try w=2.
7(2) - 4 = 10
2(2)+5 = 9
Ok, so far it seems like A is greater, lets try w=3:
7(3) - 4 = 21-4 = 17
2(3) + 5 = 14
So, I have two cases where A is greater, but the text is saying that the answer should be D because the book i’m using (GRE Quant Reasoning Vol 1) states set the problem up as:
7w-4 ? 2w + 5
-2w -2w
5w - 4 ? + 5
5w + 9
w = 9/5 which is 1.8 as a decimal which also proves that w>1.
The text states that D should be the correct answer. Can anyone explain why?

Thank you,

Dhruv

2

Hi, so you’ve proved that A can be greater than B. The book proved that they can be equal.
They started with 7w-4 = 2w+5, on solving it we will get w=9/5 which is greater than 1. So, by substituting w=1.8 we get A and B equal. Hence, the answer is option D.(7w-4 can be greater than 2w+5, and 7w-4 can be equal to 2w+5).

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3

Use the Equal - Not equal strategy. For w=1.8 they are equal and for w=2 A is greater hence the relationship can’t be clearly defined thus D.

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