Spot what is wrong here in below Picture?

Can you identify the hidden rebus in the image below?

What's a single-digit number with no value?

You have three orange, two pink and five purple balls in the drawer beside your bed. There is no electricity and the room is entirely dark. How many balls must you take out to ensure at least one ball of each colour at least?

You walk into a room and see a bed. On the bed, there are two dogs, five cats, a giraffe, six cows, and a goose. There are also three doves flying above the bed. How many legs are on the floor?

In order to complete the racing competition, the Mexico racetrack has to submit its top and the most famous three horses to win the competition. Due to an electrical storm, all the records are cleared and no one knows which horse holds the record. They all look identical and it becomes even more difficult to differentiate the horses. There are 25 horses in the Mexico racetrack. But there can be only five horses at a time on the track. What will the least number of races that can be conducted to find out the three fastest horses?

Rearrange the letters in "new door" to make one word.

I have an eye but still cannot see.

Who am I?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

What does this Rebus Picture means ?