Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

What is always in front of you but can’t be seen?

A number with an interesting property:

When I divide it by 2, the remainder is 1.
When I divide it by 3, the remainder is 2.
When I divide it by 4, the remainder is 3.
When I divide it by 5, the remainder is 4.
When I divide it by 6, the remainder is 5.
When I divide it by 7, the remainder is 6.
When I divide it by 8, the remainder is 7.
When I divide it by 9, the remainder is 8.
When I divide it by 10, the remainder is 9.

It's not a small number, but it's not really big, either.
When I looked for a smaller number with this property I couldn't find one.

Can you find it?

What is common among 11, 69, and 88?

I always drive my customer away.

Who am I?

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

You can see three almost identical images below. Can you spot the odd one out from them?

What Adam and Eve do not have but the rest of the people have?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.