You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

How many triangles are there in the picture below?

The cream is heavier than Milk. True or False?

Move four matchsticks to the below square to form three squares?

In a classic wine shop, the list of three most popular wines are:
- The cost of 1 French wine bottle: 500$
- The cost of 1 German wine bottle: 100$
- The cost of 20 Dutch wine bottles: 100$

John entered the wine shop and he needs to buy
- All three types of wine bottles.
- Needs to buy Dutch wine bottles in multiples of 20.
- Need to buy 100 wine bottles in total.

John has only 10000$. How many wine bottles of each type, John must buy?

Which Travels Faster? Solve below famous picture riddle:

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Can you quickly find which two matchstick figures are identical?

What can jump higher than a building?