Why is a river so rich ?

What has a ring but no finger?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

I am 5 letters long.
My first two tell you who I am
My first 3 could be a medicine
My last three reversed could be a young boy.
My 4th, 3rd and 2nd in that order could be a fruit drink.
If you have me you may hang me round your neck
WHAT AM I ?

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?

There are three boxes which are labeled as Rs100, Rs150, and Rs200. One box contains two notes of Rs. 50. The second box contains one note of Rs50 and one note of Rs100 The third box contains two Rs. 100 notes. All boxes are labeled incorrectly.

What is the minimum number of boxes you must check in order to label all boxes correctly?

Can you count the number of triangles in the given picture?

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?