Lesson: QC Strategy - Miscellaneous

Comment on QC Strategy - Miscellaneous

In the Geometry example. Angle X should be 70 and that means angle y is 40. From this I think that the answer is A and not B.

I am sorry. Answer B is correct. I looked at the wrong sides. Thank you

The '175 flashcards' link ain't working
greenlight-admin's picture

That's odd. I just checked, and it worked for me on two different computers. Is it possible your computer's settings are preventing the link from working?

Yeah, I think it was a browser issue. Works fine now. Thanks.
greenlight-admin's picture

Good to hear!

Cheers,
Brent

Please can you show the detailed solution of the square root comparison question
greenlight-admin's picture

You're referring to the question that appears at 1:10 in the video.

QUANTITY A: √(121 x 6400 x 90000)
QUANTITY B: √(8100 x 25600 x 12100)

We can apply a useful root property that says:
√(abc) = (√a)(√b)(√c)
For example: √(9 x 16) = (√9)(√16) = (3)(4) = 12

We get:
QUANTITY A: (√121)(√6400)(√90000)
QUANTITY B: (√8100)(√25600)(√12100)

Evaluate each part to get:
QUANTITY A: (11)(80)(300)
QUANTITY B: (90)(160)(110)

From here we can either calculate both quantities, or we can use the MATCHING OPERATIONS strategy. Let's use matching operations.

Divide both quantities by 11 to get:
QUANTITY A: (80)(300)
QUANTITY B: (90)(160)(10)

Divide both quantities by 80 to get:
QUANTITY A: (300)
QUANTITY B: (90)(2)(10)

At this point, we can see that Quantity B is greater.

Answer: B

Great! Please is there a video module where you taught how to get the square-root of large numbers?

Hi Brent!

Thanks for the awesome video.

Please, can you give an example of the 4th strategy you mentioned in the video "Pay close attention to shared information"?
greenlight-admin's picture

The shared information is extra information that apply to both quantities.

So, if the two quantities were...
QUANTITY A: x
QUANTITY B: -3y²
...an example of shared information might be something like: x > 0

Without that shared information, the correct answer would be D.
However, if we consider the shared info (which is sometimes easy to forget), then the correct answer is actually A.

Cheers,
Brent

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QC Strategies

When you encounter a Quantitative Comparison question, be sure to consider which strategy might best apply: 

 

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