An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

John and Jenni are a married couple. They have two kids, one of them is a girl. Assume safely that the probability of each gender is 1/2.
What is the probability that the other kid is also a girl?

Hint: It is not 1/2 as you would first think.

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

How many sides does a circle have?

The pound is not a finish.

We are sharing a few instructions below, which you have to use in any suitable order to modify the above sentence such that the end sentence is a scientific fact.

- Eliminate a letter and supplement another in its place.
- Take away one word.
- Remove one letter from one word.
- Get rid of two letters from one word.
- Swap a word with its antonym.

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

I can be cracked, made, told, and played. What am I?

Can you replace the question mark with the correct number?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Why is it very easy to weigh a fish?