What occurs twice in a week, once in a year but never in a day?

Spot 5 differences in two Christmas tree below:

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?

You have 1023 apples and 10 bags. You have to distribute these apples in these 10 bags in any way you choose. But when I ask for a certain number of apples you have to give them in terms of bags without transferring the apples from other bags. How do you distribute the apples?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Who has married many women but was never married?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

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

There is something which is always coming but never arrives?