What number should come in place of the question mark below?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

There are three boxes. One is labeled "APPLES" another is labeled "ORANGES". The last one is labeled "APPLES AND ORANGES". You know that each is labeled incorrectly. You may ask me to pick one fruit from one box which you choose.

How can you label the boxes correctly?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

What goes up but never comes down?

How many letters are in the alphabet?

What can you catch but never throw?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

15 caves are arranged in a circle at the temple of doom. One of these caves has the treasure of gems and wealth. Each day the treasure keepers can move the treasure to an adjacent cave or can keep it in the same cave. Every day two treasure seekers visit the place and have enough time to enter any two caves of their choice.

How do the treasure seekers ensure that they find the treasure in the minimum number of possible days?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'