Can you find the missing piece of the Porsche?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

Prove that the below maths equation is true.

8 + 8 = 91

What brings you down but never up?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

If 21x = 79x, what is the value of x?

People put me on the table and cut me but do not eat me. What am I?