What's the best place to go shopping in the ocean?

How many triangles can you find in this given picture?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

Can you solve below mathematical equation?

2^1234 - 2^1233

I ask Joseph to pick any 5 cards out of a deck with no Jokers.

He can inspect then shuffle the deck before picking any five cards. He picks out 5 cards then hands them to me (Jack can't see any of this). I look at the cards and I pick 1 card out and give it back to Joseph. I then arrange the other four cards in a special way, and give those 4 cards all face down, and in a neat pile, to Jack.

Jack looks at the 4 cards i gave him, and says out loud which card Joseph is holding (suit and number). How?

The solution uses pure logic, not sleight of hand. All Jack needs to know is the order of the cards and what is on their face, nothing more.

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

Why do we preferably have round manhole covers and not square ones?

What Time Should the last watch show in the below figure?