A TRAVELLER COMES TO A FORK IN THE ROAD WHICH LEADS TO TWO VILLIAGES IN ONE VILLIAGE THE PEOPLE ALWAYS TELL LIES AND IN THE OTHER VILLIAGE THE PEOPLE ALWAYS TELL THE TRUTH THE TRAVELLER NEEDS RIDDLES WITH ANSWERS TO SOLVE - PUZZLES & BRAIN TEASERS

P3 can only be certain of his cap if 1 & 2 are both white. Since he is not certain then 1 & 2 must be either white/red or red/red. 2 knows this but the only combination that he will be able to know the colour of his own cap is if he sees that 1 is wearing a white cap. 1 knows this but as 2 remains uncertain then 1 must be wearing a red cap. Did you answer this riddle correctly?
YES  NO  

Give 3 full, 1 half-full and 3 empty bottles to the first person.
Give 3 full, 1 half-full and 3 empty bottles to the second person.
Give 1 full, 5 half-full and 1 empty bottle to the third person. Did you answer this riddle correctly?
YES  NO  

One. The old man is going to New York alone. Did you answer this riddle correctly?
YES  NO  

This problem can be best solved using the pigeonhole principle.

The argument will go like this:
Assume that all the non-bald people in NYC have different number of hairs on their head. The population is about 9 million and let us assume that there are 8 million among them who are not bald.

Now, those 8 million people need to have different number of hairs. On an average, people have just 100, 000 hairs on their head. If we keep on assuming that there is someone with just one hair, someone with two, someone with three and so on, there will be 7, 900, 00 other people left who will have more than 100, 000 hairs on their head and need different number of hairs.

Now, as per this assumption, if we keep increasing one hair for each person, to make everybody hair different in numbers, we will come across someone with 8, 000, 000 hairs. But that is practically impossible (even 1, 000, 000 is impossible). Thus there must be two people who are having same number of hairs. Did you answer this riddle correctly?
YES  NO  

Country people could eat their forest preserves and city people could eat their traffic jams. Did you answer this riddle correctly?
YES  NO  

That's where their funny bones are. Did you answer this riddle correctly?
YES  NO  

A mountain range. Did you answer this riddle correctly?
YES  NO  

Russians Did you answer this riddle correctly?
YES  NO  

Make applesauce Did you answer this riddle correctly?
YES  NO  

17 mins.

The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.

Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.

1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)

Total time = 2 + 2 + 10 + 1 + 2 = 17 mins Did you answer this riddle correctly?
YES  NO  

A window. Did you answer this riddle correctly?
YES  NO  

Zebra Did you answer this riddle correctly?
YES  NO  

Snow. Did you answer this riddle correctly?
YES  NO  

The couple is either a man and his daughter or an uncle and his niece. Did you answer this riddle correctly?
YES  NO  

1 hour! Take the 1st pill right away, half an hour later take the 2nd and half an hour after that the 3rd. Total time spent: 1 hour! Did you answer this riddle correctly?
YES  NO