What does this rebus riddle means ?

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

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?

How many triangles can you count in the figure given?

Count the number of triangles in the below picture?

Why is a river so rich ?

I can be cracked, made, told, and played. What am I?

Solve the rebus riddle in the picture below.

When monkey rotate the gear, which mark will be hit 1 or 2 ?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?