What is common among 11, 69, and 88?

Why is a river so rich ?

In a basket of apples,
when counted in twos, there was one extra
when counted in threes, there were two extra when counted in fours, there were three extra
when counted in fives, there were four extra
when counted in sixes, there was five extra.

However, if the apples were counted in sevens, no extra apple was left. Can you calculate the minimum number of apples that were present in the basket?

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

Count the number of triangles in the below picture?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

Who is that with a neck and no head, two arms and no hands? What is it?

What runs around the whole yard without moving?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?