Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Accidentally, two trains are running in the opposite direction and enter a tunnel that is 200 miles long. A supersonic bird that has fled the lab and taken shelter in the tunnel starts flying from one train towards the other at a speed of 1000 mph. As soon as it reaches the second train, he starts flying back to avoid collision and meets the first train again at the other end. The bird keeps flying to and fro till the trains collide with each other.

What is the total distance that the supersonic bird has traveled till the trains collided?

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

Out of the nine cats that you can see in the picture, there are only two that are completely identical. Can you find them out?

Why do we preferably have round manhole covers and not square ones?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

1. Where does Easter come from before Valentine's Day?

2. Do you know what is in the middle of Valentine's?

3. What did the lady bee say to the man bee on the occasion of Valentine's Day

My thunder comes before lightning.
My lightning comes before my rain.
My rain dries up all the land it touches.

Who am I?