Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

I have two sand hourglasses:
1. A 7 minute one and
2. An 11-minute one.

Using just these 2 sand hourglasses, how can I measure time as 15 minutes?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Can you make a fire with just a single stick?

A pregnant woman is preparing to name her seventh child. Her children's names so far are Dominique, Regis, Michelle, Fawn, Sophie, and Lara. What will she name her next child -- Jessica, Katie, Abby or Tilly?

You have four chains. Each chain has three links in it. Although it is difficult to cut the links, you wish to make a single loop with all 12 links. What is the fewest number of cuts you must make to accomplish this task?

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

Can you find out the missing number in the grid?

In the addition below, all digits have been replaced by letters.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?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?