What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

Can you find a five letter word that is left with only two letters if one is removed?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

Find the 8 in the below-given Image.

Peter wakes up daily to pick up his cycle and crosses the border between Spain and France daily with a bag on his shoulder. He is investigated daily by the officials but they don't find anything suspicious.

If we tell you that he is smuggling something what would it be?

You have a basket containing ten apples. You have ten friends, who each desire an apple. You give each of your friends one apple.
Now all your friends have one apple each, yet there is an apple remaining in the basket.
How?