What is the next number in this matchsticks series riddle?

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

The more you take me, the more you leave me behind.
Who Am I?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

A gardener planted the Lemon trees in a mathematical ordered way (i.e. he planted a tree in rows).
He created a total of 19 rows of trees.

Note: There should be more than 2 trees to count as a row.

What is the minimum number of trees required by the gardener to have 19 rows of trees?

After undergoing a successful eye operation, A blind girl has just boarded a train to her home. The doctor asked her to open the bandages after 3 hours. On her train journey, she opened the bandages and within a fraction of the time she commits suicide by jumping off the train.

Though her operation was successful, Why did she commit suicide?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

When we see 2 but call 10?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?