Which number should replace the question mark?

Count the squares in the matchstick puzzle below?

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

Using Only Five 5's and any mathematical operator make sum as 37

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

Can it be possible to build a house that has all its four walls facing towards the South?

In the figure, you can see nine stars. What you have to do is connect all of them by using just four line and without lifting your hand i.e. in a continuous flow.

You can hear me, but you can't touch or see me.

What am I?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?