What does this rebus puzzle means ?

What can go through glass without breaking it?

Women do it once a year after they turn 19 but men get to do it only once in a lifetime. What is it?

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

You can hear me, but you can't touch or see me.

What am I?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

What is always in front of you but can’t be seen?

In a school, 280 students studied chemistry, 254 students studied physics and 280 students studied biology.

97 students studied chemistry as well as physics, 138 students studied physics as well as biology and 152 students studied chemistry as well as biology.

73 students studied all the three branches.

Can you find out the total number of students?

Three cars are driving on a track that forms a perfect circle and is wide enough that multiple cars can pass anytime. The car that is leading in the race right now is driving at 55 MPH and the car that is trailing at the last is going at 45 MPH. The car that is in the middle is somewhere between these two speeds.
Right now, you can assume that there is a distance of x miles between the leading car and the middle car and x miles between the middle car and the last car and also, x is not equal to 0 or 1.
The cars maintain their speed till the leading car catches up with the last car and then every car stops. In this scenario, do you think of any point when the distance between any two pairs will again be x miles i.e. the pairs will be x distance apart at the same time ?