# Lesson: QC Strategy - Miscellaneous

## Comment on QC Strategy - Miscellaneous

### In the Geometry example.

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

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

### The '175 flashcards' link ain

The '175 flashcards' link ain't working ### That's odd. I just checked,

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

Yeah, I think it was a browser issue. Works fine now. Thanks. Good to hear!

Cheers,
Brent

### Please can you show the

Please can you show the detailed solution of the square root comparison question ### You're referring to the

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.

### Great! Please is there a

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

### Hi Brent!

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"? ### The shared information is

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