If the developer had corrected 20 bugs he would get 20 x 10000 = 200000$ . Since he got only 125000 it means that he had to give back 75000.  So 75000/5000=15

The rule will be:  “the person who makes the 2nd highest bid will get the car”.  Its like a riddle of 2 persons riding horses and the rule is that the horse that will be 2nd will win the race but you want them to ride as fast as possible so since it is the person’s horse that wins and not the person each of  them will ride on his friend horse hoping he gets 1st to his horse that his friend rides will get 2nd so he’ll get the price.

The same logic is here too. If you give a too much lower bid you  will lose’ so you choose a bid close enough to the real and maybe a little more hoping someone will give a higher bid that you…

Take 7 cards from pile 1 (11) and put it onto pile 2 (7) so now we have 4 14 6.
Take 6 cards from pile 2 (14) and put it onto pile 3 (6) so now we have 4 8 12.
Take 4 cards from pile 3(12) and put it onto pile 1 (4) so we got 8 8 8.

1) start  both hourglasses
2) After 11 minutes turn the 11 hourglass upside down ()reactivate it)
3) After 13 minutes the 2nd hourglass finished so 2 minutes passed from the 11 hourglass
4) So now turn the 11 hourglass again upside down and it will finish after 2 minutes so we measured 15 minutes total

Since there are 99 people that the last one sees, then
1) equality between the number of white and red is not possible
2) one of the groups is odd.

He will count how many there are in each group and say the color of the odd group.
The next one after him will count the stripes in front of him and if he sees an equal number of the same color as the first
said then it is his color otherwise it is the other color.

(Starting with the second prisoner, everyone sees how many are in front of them and know how many left before them,
and what the first one said (meaning which group is the even)) and so they can, in the worst case,
reach a score of 99, because only the person in the rear is guessing.

If there was only one person colored he will see 2 not colored so he wouldn’t laugh. If there are 2 colored persons then each of them sees one colored and one clean. So he will think: if I’m also clean than we both laugh at the colored person, but why does the colored person laugh too? that means that he also sees a colored person so that means I’m colored too, so he’ll stop laughing and so will the other colored person. the final state will be that the clean person will keep on laughing and the other two will stop after a short time. In case all of them are dirty than the process will go like this: I thing that I’m clean and so does the person next to me, but since he sees that  the 3rd person keeps laughing he understands the he is colored too. that brings us to the 2nd option that if there were 2 colored and one clean they will stop laughing. If they don’t stop that means I’m colored too. So at that point they will all stop laughing.

The riddle is not formulated clearly. I think that "she randomly moves to one of the two adjacent houses" means that she moves to one of the two adjacent houses she went
during the last two days. For example: If we had only 6 houses then on day 1 she can go to number 1 or 6 and if she went to 1 then on day 2 she can go to 2 or 6 and if she
 went to 6 then on day 3 she can go to 3 or 5 and so on. So if one day she goes left and on the other right the last one will be 1+(100/2)=51

186

The difference between the numbers is a multiplication of 11. Starts with 11 and than 22,33,44 so the next in line is 55. therefor   131+55=186

The chef. As said: “One morning, Mr Smith woke up”, so its not too late in the morning (Although some persons are already awake), and there is no reason to start preparing Lunch.