What number comes next in this sequence:
7 8 5 5 3 4 4 _

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?

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

What does below pictogram mean?

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?