What is the Surname of Barbie Doll?

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

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

There’s a girl who has a large family. She has an equal amount of brothers and sisters, but each brother only has half as many brothers and sisters. What’s the correct amount of brothers and sisters?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

In a supermarket, there is an intelligent glass pane before a refrigerating unit. This glass pane allows cherries and apples through it but does not allow grapes and Orange to pass through it.

Can you identify the rule that the glass pane is following?

Why is the Hole below a Lock?

How many letters are in the alphabet?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

I have eight fingers and two thumbs but I do not live. What Am I?