Decode below rebus
D
N
A
T
S , D

There was a minor accident with a doctor's son but the doctor noticed no major injury. After the treatment, the father of that doctors son is sitting with the son of the doctor without the doctor being in the room.

How can this be possible?

What does this rebus mean?

O
N
C
E
TIME

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

If you say my name, I will no longer exist. What am I?

Before Mount Everest was discovered, what was the highest mountain in the world?

Can you fill the blank with the correct number?

6 30 870 756030 _____

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?