What happened when the wheel was invented?

Using Only Five 5's and any mathematical operator make sum as 37

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

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

What does this Rebus Picture mean?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

People put me on the table and cut me but do not eat me. What am I?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?