Best long riddles for teens

Pronounced as one letter, And written with three, Two letters there are, And two only in me. I’m double, I’m single, I’m black blue and gray, I’m read from both ends, And the same either way.

You have two cups. One cup is filled with black coffee and another cup is filled with black tea. Both cups are filled with equal quantity of respective beverages. Take one spoonful of black tea and mix with the cup of black coffee. Then take one spoonful of black coffee and mix it with the cup of black tea. Now tell, me which cup has more liquid in it? Does the cup of black tea has more liquid or black coffee has more liquid?

Farmer Brown came to town with some watermelons. He sold half of them plus half a melon and found that he had one whole melon left. How many melons did he take to town?

One winter day, there was a man standing in the middle of someone's front yard. The person stayed there for several weeks without moving and the owner of the yard didn't mind. Eventually the man left. Who was the man?

A dead body is found at the bottom of a multistory building. Seeing the position of the body, it is evident that the person jumped from one of the floors, committing suicide. A homicide detective is called to look after the case. He goes to the first floor and walks in the room facing the direction in which the body was found. He opens the window in that direction and flips a coin towards the floor. Then he goes to the second floor and repeats the process. He keeps on doing this until he reaches the last floor. Then, when he climbs down he tells the team that it is a murder not suicide. How did he come to know that it was a murder?

Sometimes I am loved, usually by the young. Other times I am dreaded, mostly by the old ones. I am hard to remember, also hard to forget. And yet if you do, You'll make someone upset. I occur every day everyone has to face me. Even if you don't want it to happen; embrace me. What am I?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test it was a blank sheet of paper with a solitary question on it: "What is risk?" Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word! What did he write?

Romeo and Juliet are found dead on the floor in a bedroom. When they were discovered, there were pieces of glass and some water on the floor. The only furniture in the room is a shelf and a bed. The house is in a remote location, away from everything except for the nearby railroad track. What caused the death of Romeo and Juliet?

A boat has a ladder that has six rungs, each rung is one foot apart. The bottom rung is one foot from the water. The tide rises at 12 inches every 15 minutes. High tide peaks in one hour. When the tide is at it's highest, how many rungs are under water?

Dean Sam and Castiel are three brothers. Interestingly their current age is prime. What's more interesting that difference between their ages is also prime. How old are they?