Why is a river so rich ?

The more of this there is, the less you see. What is it?

To attend world science seminar, A famous chemist from Mexico visit
London. In the lab, the scientist was killed and his six assistants were under suspicion of killing the chemist.
Name of six assistants: Austin, Wayne, Dege, Oscaru, Lingard, and Rojo.
He left a note "76-20-44 79-16-22-7"

A local detective Jack was called to solve the case,

After reading the note, Jack instantly asked the police to arrest the murderers.

Who are the murderers?

When is the top of a mountain similar to a savings account?

Count the number of triangles in the given picture.

A car meter reading shows 72927 miles a palindromic number.
what is the minimum number of miles you would need to travel to see another palindromic number on the car meter reading?

Count the number of lines in the image below ?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

Can you spot the man between the coffee bean in the picture below ?