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

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

Can you decipher the below rebus?

PBLUESAISNUERSES

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 ?

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

What can you catch but never throw?

Can you find out the total number of triangles in the given figure?

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?