If grammar is important to you, below are some suggested changes to "Your task is to calculate how much blank pages do you need."

"Calculate how many blank pages you need."
"Calculate how much paper you need."
"Your task is to calculate how many blank pages you will need."

If you care about grammar way too much, like me, here are the reasons for the suggestion:
Proper usage is "many" where things can be counted ("How many pieces of cake are you gonna eat? Many pieces") and "much" when they are not countable("How much cake are you gonna eat? Soooo much cake.").

The phrase "do you need" is not a big deal, but most native speakers would only use it in a question, "do you need x pieces of paper?" or "how much paper do you need?" and would use something like "you will need" or simply "you need" in this case.

Is it necessary to skimp on whitespace and leave out curly braces?
They are free, easy, and make the code more readable to more people!

Readability is a hugely important factor for "best practice."
I had to spend some real time trying to make sense of this, admitedly, CLEVER solution.

Someone who thinks this is really best practice care to explain your reasoning?

PS. this is honest, I'm not trying to make trouble!

Um... I don't think this should work.

Profoundly simple kata with only 2 tests.
Perhaps add an input validation portion so there's something to solve here

Suggestions:
Make the function inputs more expressive
Specific the output should be to two decimal places

Nice kata! Clear assignment, no tricks, thorough tests

I don't understand where the passengers are going?
Why are the functions incrementing and decrementing?
Is this Callback City where addresses are +=10 or -=10?

Ok. I understand removing confusion, but you should still write it a prompt that is more clear than
"You have to write a function pattern which creates the following pattern upto n number of rows."

That doesn't make any sense.

It would much more clear to lead with something like this:
"Write a function (named "pattern") that accepts only a postive integer n, and returns a string containing rows of every even number up to n, repeated n number of times."

Then everything you write afterwards has some context.
Again, nice, fun challenge! The prompt just needs tuning.

HELP me please!
I just cannot get past "Expected: null, instead got: [null]"
I've even added a check before each return to change any [null] into null, no luck!

The challenge should be explained clearly and not rely only on the examples. As it is, without examples this is impossible to even get started. Fun challenge though!

Lost numbers are 4, 8, 15, 16, 23, 42
http://lostpedia.wikia.com/wiki/The_Numbers