Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Do You See It?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

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

Andrew sees a very rare bird named "Ruppell's vulture". Soon Andrew was dead. Can you explain the mystery, Mr. Sherlock?

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

A bus driver was heading down a street in Mexico. He went right past a stop sign without stopping, he turned left where there was a "no left turn" sign, and he went the wrong way on a one-way street. Then he went on the left side of the road past a cop car. Still - he didn't break any traffic laws. Why not?

In The 1st month of this year(the year 2013), I noticed that the date 13-1-13 (13 January 2013) is special.

This date is special as:

Date * Month = Year.

Can you figure out which year of this century has a maximum number of such dates?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?