why number 8549176320 is one of a kind?

Spot 5 differences in two Christmas tree below:

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

Rebus Puzzle Definition: A rebus is an illusion device that uses pictures to represent words or parts of words.
What does This Rebus Puzzle Identify?

Find the next number in the series below

21 32 54 87 131 ?

Prove that twice of ten is the same as twice of eleven.

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

In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?