What brings you down but never up?

A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.

After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.

How much loss did the bookkeeper face?

You are driving down the road in your car on a wild, stormy night, when you pass by a bus stop and you see three people waiting for the bus

An old lady looks as if she is about to die.
An old friend who once saved your life.
The perfect partner you have been dreaming about.
Knowing that there can only be one passenger in your car, whom would you choose?

There is something which you can be arrested for attempting but not for successfully completing.

Find The Odd One Out

1. FLOW
2. SNIP
3. TRAP
4. DRAW
5. BACK

In order to complete the racing competition, the Mexico racetrack has to submit its top and the most famous three horses to win the competition. Due to an electrical storm, all the records are cleared and no one knows which horse holds the record. They all look identical and it becomes even more difficult to differentiate the horses. There are 25 horses in the Mexico racetrack. But there can be only five horses at a time on the track. What will the least number of races that can be conducted to find out the three fastest horses?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not.

Is a married person looking at an unmarried person ?

In a school, 280 students studied chemistry, 254 students studied physics and 280 students studied biology.

97 students studied chemistry as well as physics, 138 students studied physics as well as biology and 152 students studied chemistry as well as biology.

73 students studied all the three branches.

Can you find out the total number of students?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?