Why are televisions attracted to people?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

Three men in a cafe order a meal the total cost of which is $15. They each contribute $5. The waiter takes the money to the chef who recognises the three as friends and asks the waiter to return $5 to the men.

The waiter is not only poor at mathematics but dishonest and instead of going to the trouble of splitting the $5 between the three he simply gives them $1 each and pockets the remaining $2 for himself.

Now, each of the men effectively paid $4, the total paid is therefore $12. Add the $2 in the waiters pocket and this comes to $14. Where has the other $1 gone from the original $15?

Find the missing number in the sequence.

3 5/3 7/5 11/7 ? 17/11

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

I am white when I am dirty, and black when I am clean. What am I?

Next Number in the Series,

5, 16, 49, 104, ?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

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

What makes this number unique: 8,549,176,320?