Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

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

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

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?

Consider this about a word: The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

Can you count the number of quadrilaterals in the picture below?

If a wheel has 54 spokes, how many spaces are there between the spokes?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

The owner of a popular clothing store comes up with his own method of pricing items. A vest costs $8, socks cost $10, a tie costs $6, and a blouse costs $12. Using the owner’s method, how much would a pair of underwear cost?