Name a key which is hardest to turn.

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

Use the numbers 2, 3, 4 and 5 and the symbols + and = to make a true equation. Conditions: Each must be used exactly once and no other numbers or symbols can be used.

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

In the image below, can you find the value of an angle(y)

Find the next number in the series.
1 10 24 43 67 ?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Find the missing number in the sequence below:

A car is crossing a 20 km-long bridge. The bridge can support at most 1500kg of weight over it. If somehow, the weight on the bridge becomes more than that, it will break.

Now, the weight of the car is exactly 1500kg. At the midway, a bird comes and sits on the roof of the car. This bird weighs exactly 200 grams.
Can you tell if the bridge breaks at this point or not?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?