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

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

What brings you down but never up?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?