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?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

In the picture given below, can you find out which digit will take place of the question mark?

Take one out and scratch my head, I am now black but once was red. What am I?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

Seven Robbers robbed a bank and hide the coins in a lonely place.
They decide to divide the money equally the next morning. Two greedy robbers decided to cheat the others and reach the place at night. They equally divided the coins between them, one coin left. So they called another robber and then they decided to divide equally among the three. Sadly again one coin left. The same thing happened to the 4th 5th and the 6th robber.
However, when the 7th robber reached in the morning, they can divide the coins equally.

How many coins were there in total?

Can you write down eight eights so that they add up to one thousand?

I’m tall when I’m young, and I’m short when I’m old. What am I?