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

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Four cars come to a four-way stop, each coming from a different direction. They can’t decide who got there first, so they all go forward at the same time. All 4 cars go, but none crash into each other. How is this possible?

John was piloting a plane behind a car but was never able to overtake it. Why?

Which is the correct shadow of the bird?

French Police inspects a room where there are no windows, no doors, no tables and is almost empty expect there is just a puddle of water. They found a dead man who obviously hung herself from the ceiling, but they are not able to figure out how this had happened.

John and Jacob entered the crime scene and easily able to solve the case.

How did the man die?

I look at you, you look at me I raise my right, you raise your left. What am I?

John was gifted a new Hayabusa. He drove x miles at 55mph. Then he drove x+20 miles at 40mps. He drove his bike for 100 minutes. How much distance did he travel?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

A little girl goes to the store and buys one dozen eggs. As she is going home, all but three break. How many eggs are left unbroken?