How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

What kind of band never plays music?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

Can you find the ages of a son, father and grandfather based on the following facts?
The sum of the ages of grandfather, father and son is 140 years.
The age of the son in months is the same as the grandfather in years.
The age of the son in days is the same as the father in weeks.

You need to remove two matchsticks to make the below equation true. Can you do it ?

What is the word or phrase?

How many sides does a circle have?

Why is it very easy to weigh a fish?