why number 8549176320 is one of a kind?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

A gardener planted the Lemon trees in a mathematical ordered way (i.e. he planted a tree in rows).
He created a total of 19 rows of trees.

Note: There should be more than 2 trees to count as a row.

What is the minimum number of trees required by the gardener to have 19 rows of trees?

How many words can a pen with half refill write?

What English word has three consecutive double letters?

What can you see in the middle of March and April that you can never see in any other month?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

Using Only Five 5's and any mathematical operator make sum as 37

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

Count the number of times the letter "F" appears in the following paragraph:

FAY FRIED FIFTY POUNDS OF
SALTED FISH AND THREE POUNDS
OF DRY FENNEL FOR DINNER FOR
FORTY MEMBERS OF HER FATHER'S FAMILY.