How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Client Dempsey living in one of the East Coast states of the U.S. was talking to Landon Donovan, who was living in the West Coast state of the U.S.

Dempsey: What time is it?
Donovan: Wow, It is the same time here.

How is this possible?

There are a hundred statements.

First person says: At least one of the statements is false.

Second person says: At least two of the statements is false.

Third person says: At least three of the statements are false.

Fourth person says: At least four of the statements are false.

..

..

..

Hundredth person says: At least a hundred of the statements are false.

Analysing it, how many statements do you think are false and how many are true?

What's a single-digit number with no value?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

A family is trapped in a jungle. There is a bridge which can lead them to safety. But at one time, the bridge can only allow two people to pass through. Also, all of them are afraid of the dark and thus, they can't go alone.

Father takes 1 minute to cross, the mother takes 2 minutes, the son takes 4 and the daughter takes 5 minutes. While crossing the time taken will be according to the slower one. How can they all reach the other side in the minimum possible time?

There is a unique number which when multiplied by any number from 1 to 6, we will get the new number that contains the same digits only.

Can you find that number?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?