Uncovering the Hidden Simplicity of Similar Triangles

[karush]

View attachment 9548
This seems to be rather common GRE Exam Question
Which appears to harder that what it is
It looks like a similar triagle solution
$\dfrac{800}{7000}=\dfrac{x}{1400}$

 

[tkhunny]

This seems to be rather common GRE Exam Question
Which appears to harder that what it is
It looks like a similar triagle solution
$\dfrac{800}{7000}=\dfrac{x}{1400}$

800/7000 = x/1400

It's a little bit of smoke.

80/700 = x/1400

8/70 = x/1400

8/7 = x/140

8/1 = x/20

Look easier?

Anyone whose first move is to produce 112,000 = 700x simply isn't paying attention.

 

[HallsofIvy]

"Anyone whose first move is to produce 112,000 = 700x" solves problems like this by immediately plugging numbers into a calculator!​

 

[karush]

800/7000 = x/1400

It's a little bit of smoke.

80/700 = x/1400

8/70 = x/1400

8/7 = x/140

8/1 = x/20

Look easier?

Anyone whose first move is to produce 112,000 = 700x simply isn't paying attention.

actually the answer is
x=160