O_er_t_o_

Complete the missing letters of the given word.

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

You are given 2 eggs.
You have access to a 100-storey building.
Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100th floor, Both eggs are identical.
You need to figure out the highest floor of a 100-storey building an egg can be dropped without breaking.
Now the question is how many drops you need to make. You are allowed to break 2 eggs in the process

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

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?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?