Pointlessly difficult to get a meal here, isn't it?

Carl and Mike are two great friends. They grew up together and stay together a lot. They both LOVE the delicious turkish meal Kebab and eat it very often.

One day Carl comes to Mike with great news.

"A new fantastic kebab shop recently opened in town!", said Carl. "There are already a lot of kebab shops in town, why this should be so 'fantastic'?" thought Mike.

"Tell me more" said Mike.

"This is truly the best, Mike! The owner is the most renowned kebab chef of all time and they have a lot of wonderful ingredients and the place is great and is really cheap and..."

"Calm down!" shout Mike. "From what you say I think you've already been there".

"Yes" replied Carl. "And there is something more I have to tell you. This is no normal place. They have a lot of costumers and can't handle them all. They've come with a very peculiar solution for it".

"Riddles."

"What? Riddles?"

"Yes. Every costumer, to enter the shop, has to answer a riddle in one minute. After the minute passes, if the answer is correct, the doors open and he can enter to eat. You just have to say the solution, that's it! Mine was really silly: 'If a brick weighs one kilogram plus half brick, how much does a brick weight?'"

"??" quickly answered Mike. BONUS! Solve this!

"Exactly! You should really give it a try!"

Really curious Mike decided to go to the kebab shop the same evening.

Upon arrival Mike was faced with a big door with a television screen on it. It was written "PRESS THE BELL". Mike pressed it.
Very soon the riddle appeared. "WOW! So Carl wasn't lying after all!" he thought:

WHAT'S IT THAT MAKES POTATO IN MANDATORY AND PATIENCE IN CAT?

"...Wait, what? Mandatory potatoes? What's this? Think, think!"

The screen changed in a big 60 number. And started to countdown. 59, 58, 57..

"The cat is patient. Also the potato. No, no..."

...45, 44, 43..

"Argh! The time is flowing! ...Wait. I'm really struggling to solve a riddle just to eat a kebab? There is another shop just 400 mt from here. What I'm doing??" thought Mike.

...32, 31, 30...

"I'm not going to do this. I just want to eat."

"You know what? This is nonsense. There is a kebab shop just around the corner, I'm going there. Goodbye." shouted Mike, and left.

...10, 9, 8...

...3, 2, 1... CLICK! and the door opened.

Can you explain why?

• Now that you've accepted an answer, is there actually a solution to Mike's riddle? Nov 10, 2014 at 7:10

Mike said "This is nonsense", which is pretty true. The door didn't open right away; as Carl said, "After the minute passes, if the answer is correct, the doors open and he can enter to eat."

Bonus:

A brick weighs 2 kg. Let the weight of a brick be $x$. "a brick weights one kilogram plus half brick" means $x = 1 + \frac{x}{2}$. Solving for $x$ yields $x=2$.

• Gotcha my friend! I made up this while I was coming back home from work (and I reeeeeeally wanted a kebab). Judging from the speed-of-answer I should make this a bit more difficult. Have my +1 Nov 7, 2014 at 18:52
• @Narmer Thanks. Did you know you can "accept" answers by clicking the green checkmark near the top left corner? I think it's customary to wait a while to give others time to answer, and then choose which answer you think is the best. I think riddles on this site tend to get answered quickly, unless they're overly complex. Don't feel too bad! Nov 7, 2014 at 19:02
• Uhm... Yes.. I'm not new to SE :) Like you said I was waiting for some other submission (although in this case I don't think they'll come like rain). Don't worry, I'll accept your answer asap. Nov 7, 2014 at 19:05
• @Narmer I just interpreted "Have my +1" as "I'm acknowledging the correct answer" and wanted to make sure you knew about accepting! Nov 7, 2014 at 19:13

"After the minute passes, if the answer is correct, the doors open"

So before the minute passes, the doors stay shut even if the answer is correct. You get a minute to shout out a pile of rapid-fire answers the way Marky Mark shouts out women's names in the film Ted. If one of them is correct before "Ja Da" finishes, Kebab King opens.

But that's not the solution at all.

"Every costumer, to enter the shop, has to answer a riddle in one minute."

A costumer (note the spelling) is one who deals in sets of clothes in the distinctive style of a culture or character. Carl is a costumer; Mike is not. A movie costume design business just opened next door, and they've been driving away the kebab shop's regular customer base. So only costumers need to answer riddles; people with other occupations just need to wait while the bouncer verifies that it isn't yet another employee of the costume business and while the busser gets a table ready.

Now for my take on the bonus:

"If a brick weighs one kilogram plus half brick, how much does a brick weight?"

Kilogram is a unit of mass, not force, and weight is a force. The answer to "If a brick's mass is 1 kg plus half a brick, what is its mass?" is 2 kg. But in spoken English, "weight" sounds like "wait", thus a brick waits a minute just like Carl and Mike have to wait a minute.

• I'm pretty sure "costumer" was a typo... Nov 8, 2014 at 6:04
• +1 for deviousness... Always use typos against the OP!!! ^^ Nov 12, 2014 at 9:54
• I think costumer make for a much better riddle, except I suspected they were misspellings. Feb 20, 2015 at 1:57

Bonus (alternative through the loophole):

We consider the weight in a weightless environment, so it's 0 (zero). 1 kilogram (a measure of mass) weighs 0 Newtons + 1/2 of the brick that weighs 0 Newtons, the total is 0 Newtons.