How can you make number one disappear by adding something to it?

Can you count the number of lines in the below picture?

What is harder to catch the faster you run?

How can you take 2 from 5 and leave 4?

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?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

Can you solve the maths in the below-given picture equation?

I am quite hot but become too cold if you remove the first two letters. What am I?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?