What does below pictogram mean?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Take number 1000 and then add 20 to it.
Now add 1000 one more time.
Now add 30.
Now add 1000 one more time.
Now add 40.
Now add 1000 one more time.
Now add 10.

What is the total?

What will you call your mother's brother's brother-in-law?

Replace the question mark with the correct number.

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

I am a number I am not an odd number I am higher than 90 I am not higher than 100 If you subtract me from 100, you get nothing. What number am I?

Decode below rebus
D
N
A
T
S , D

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?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?