What does this Rebus Picture mean?

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

Can you find out which triangle will have a bigger area among the following?
1. A triangle with sides 300, 400 and 500
2. A triangle with sides 300, 400 and 700

Different lights make me strange by changing me into different sizes. What am I?

What kind of tree can you carry in your hand?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

Count the number of triangles in the below picture?

What has 88 keys?

What is the word or phrase?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?