# Blog

## Trench diving brainteaser

By

,

Difficulty: Tricky

Did you know that the deepest place on Earth is the Mariana Trench in the middle of the Pacific Ocean? It is 11,000 metres deep – that’s over 2,000 metres greater than the height of Mt. Everest!

Jing is a fearless scientist taking her submarine to the bottom of an ocean trench nearby the Mariana Trench. The first day she starts fast, going half the distance to the bottom of the trench. The second day she halves the remaining distance to the bottom. The third day she halves the remaining distance again, getting 1000 metres away from the bottom of the trench by the end of the day.

How deep is Jing’s oceanic trench?

Scroll down or click for a hint, or the answer!

## Brainteaser hint

Try making a vertical number line and divide it by two – this represents Jing’s progress on the first day. Take the bottom half and divide that by two – this represents the second day. Divide the resulting bottom half in two again, this represents the third day. Now where would you label the remaining 1,000 metres?