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

Given below is simple addition with a defined pattern pattern:
7 + 7 = 2
8 + 8 = 4
8 + 5 = 1
6 + 9 = 3
10 + 11 = 9

Can you analyze the pattern and find out the answer for:

4 + 9 = ?

What is the difference between a jeweller and a jailer?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

What number do you get when you multiply all of the numbers on a telephone's number pad?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Three playing cards in a row. Can you name them with these clues? There is a two to the right of a king. A diamond will be found to the left of a spade. An ace is to the left of a heart. A heart is to the left of a spade. Now, identify all three cards.