What goes up but never comes down?

What do you see in the image below

What month of the year has 28 days?

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

Name a key which is hardest to turn.

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

A research team went to a village somewhere between the jungles of Africa. Luckily for them, they reached the day when quite an interesting custom was to be performed. The custom was performed once a year as they confirmed and was performed in order to collect the taxes from every male of the region.

The taxes were to be paid in the form of grains. Everyone must pay pounds of grain equaling his respective age. This means a 20-year-old will have to pay 20 pounds of grain and a 30-year-old will pay 30 pounds of grain and so on.

The chief who collects the tax has 7 weights and a large 2-pan scale to weigh. But there is another custom that the chief can weigh only three of the seven weights.

Can you find out the weights of the seven weights? Also, what is the maximum age of the man that can be weighed for the payment of taxes?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

A boy was driving a car, a girl took a lift from her. She asked his name. The boy said - my name is hidden in my car’s number, find it if you can. After this, she got down Car number was [ WV733N ] Can you guess the name now?