This is a fairly easy quiz. Most of the questions test your understanding of the mathematical order of operations.
Please Excuse My Dear Aunt Sally is a popular mnemonic. 
I put my questions here to avoid spoilers in the OP.
Question 15 seems incomplete.
“Which is divisible by 7 without a remainder.”
Well, any multiple of 7 is divisible by 7 without a remainder. 14,21,28,35 etc.
What am I missing here? Why does the answer key say 105? That is a multiple of 7 (7x15).
Am I misunderstanding the question? I think of a remainder from long division. 15/7 is 2 with a remainder of 1. Or in fractions 2 1/7.
I missed 2 questions. 13 and maybe 15.
I didn’t want to find a pencil to figure out the square root of 4,096. I knew it was approx 200. Which is the square root of 4,000.
Your article is unavailable to those of us who use adblockers. So you’ll need to post the entire pertinent part if you want more / better responses.
As to your divisible by 7 question just above …
You’re right; either you overlooked part of their question, or they forgot to publish part of it. Any multiple of 7 is divisible by 7 without remainder. By the definition of multiplication & division. And since 7 is prime, only multiples of 7 have this property.
I can’t cut and paste the questions. Each one is a jpg.
Here’s the direct link for question 15. Or Software helpfully displays it.
Question 2 is interesting. I had to think a minute to solve it.
Looks like it was originally a multiple choice question but they failed to include any choices.
Not quite. 200 * 200 = 40,000. The 2*2 gives you a 4, then tack on all the zeros = 4 zeros. You only tacked on 3. Oops.
Computer-ish people will instantly recognize that 4,096 is a power of 2. 2^12 to be exact. So its square root is 2^(12/2) = 2^6 = 64.
For a sanity check 60*60 = 36 with 2 zeros tacked on = 3600. So a number a little bigger than 60 will get us to 4000.
Yeah! They stole this from somewhere, maybe someone’s Kahoot, where they were all presented as multiple choice, and failed to notice that one of them required that format to make sense.
I should have drank more coffee. 
I knew better than dropping those zeros.
It is a fun quiz. Nice diversion in the morning.
I used to screw that one up all the time. I eventually just memorized in words: “one hundred times one hundred is ten thousand”. By remembering it in words, not figures, that makes it harder to fall for 1000 when you mean 10000.
As to the 1/2 of 1/2 of 1/2 of 1/2 of 64, that again depends on noticing that 64 is a power of 2, and one half is also a power of 2 (2^-1) and that multiplication is commutative. So it’s:
64 / 2 = ? / 2 = ? / 2 = ? / 2 = ?
or
64 / 2 = 32.
32 / 2 = 16.
16 / 2 = 8.
8 / 2 = 4. Viola!
Quiz treats implied multiplication as the same precedence as explicit multiplication, which is the cause of like 95% of viral math problems. Therefore I hate it.
There are choices included for all of them.
I did the 1/2 of 1/2 of 1/2 of 1/2 of 64 by multiplying the fractions from left to right.
1/2 x 1/2 = 1/4
1/4 x 1/2 = 1/8
1/8 x 1/2 = 1/16
1/16 x 64 = 4
LSLGuy answer is more elegant
Where? I’m not seeing any choices.
My job includes a lot of simple mental ballpark-ish math. You get good at recognizing how to rearrange things so the computation is easier.
Tricks like: to divide by 5, instead divide by 10 by slicing off the last digit [with rounding if you care about that level of precision, just truncate if you don’t], then multiply by 2 by doubling. That’s also how I figure out 20% restaurant tips. etc.
As to the 64 times 1/2 repeated 4 times I literally pointed my mouse at each 1/2 from right to left and mentally counted them down 32, 16, 8, 4 done. Took about 3 seconds to decide how to attack it and another 3 seconds to do.
Online quizes love questions like this. But I would never code a equation like that. You have to think of the guy on call. He’s up at Operations at 1 AM trying to fix an error. (maybe a report didn’t balance and the program ended with an error code). You have to write clean code. Use parentheses. Don’t rely entirely on the order of operations.
Doh! It says so right in the text where it came from.
the DM made it harder by removing the multiple choices. We were working these old school. My math teachers rarely offered multiple choice.
Ok. Now I understand why the last question seemed incomplete.
Directly beneath each question.
Did you guys click the link to the quiz?
The Daily Fail copied all the questions, without the answers, into their article and give the solutions at the bottom. It’s not unreasonable to assume one can complete the challenge without going to the original source.
I like how the OP has questions about 2 of the quiz items, but his title says he has questions about 1 of them.
An old saw in developer land: There are 3 kinds of people: Those who can count, and those who can’t. 