Only one color, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

How is a fly different from a mosquito?

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 driving down the road in your car on a wild, stormy night, when you pass by a bus stop and you see three people waiting for the bus

An old lady looks as if she is about to die.
An old friend who once saved your life.
The perfect partner you have been dreaming about.
Knowing that there can only be one passenger in your car, whom would you choose?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

I am something people love or hate. I change peoples appearances and thoughts. If a person takes care of them self I will go up even higher. To some people I will fool them. To others I am a mystery. Some people might want to try and hide me but I will show. No matter how hard people try I will Never go down. What am I?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

People are waiting in line to board a 100-seat aeroplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise, they will choose an open seat at random to sit in. The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?