What does below rebus means ?

People are waiting in line to board a 100-seat aeroplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise, they will choose an open seat at random to sit in. The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?

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?

People put me on the table and cut me but do not eat me. What am I?

Decode this picture on T-Shirt and tell what it says ?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

Can you count the number of triangles in the given figure?

What makes this number unique: 8,549,176,320?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

What kind of tree can you carry in your hand?