What is the fastest way to double your money?

With the help clues provided in the image, can you find the 5 digit key?

Can you count the number of children in the picture below

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

What Does this text mean:

important=important

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

By adding four matchsticks, can you divide the square shown in the picture into two equal parts?

There was a greenhouse.
Inside the greenhouse, there is a white house.
Inside the white house, there is a red house.
Inside the red house, there are lots of babies.

What is It?

Rob is taller than Edwin, and Jurgen is shorter than Rob.
Of only one of the following statements, we now certainly know it is correct:

A.Edwin is taller than Jurgen
B.Jurgen is taller than Edwin
C.It cannot be determined if Jurgen or Edwin is the tallest.

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months