Signed in as:
filler@godaddy.com
Corona Virus Vaccination
2021: When I first posted this challenge, we had to 'imagine' a vaccine had been found. Now, it's for real. Yeah! :-)
... A vaccine against the coronavirus has been found and governments around the globe agree on a plan to vaccinate every living human on the planet (imagine that!). To start with, capacity to vaccinate would be limited, with just 200 people being treated on the first day. Capacity then doubles every day until the world is safe.
After how many days would the world's population be completely vaccinated?
Think You've got the answer?
Check it here
First solved in Switzerland by Vincent
Dominoes
A domino can knock over another domino 1.5 times its own height. If you start with a mini-domino just 1cm tall, How many dominos in total would it take to knock over a domino the height of the Roche Tower in Basel (the tallest building in Switzerland)?
Think you've got the answer?
Check it here
Chess doubling
There is an old legend...
...that tells of a not-so-wise king who was tricked by a merchant. In exchange for creating the game of chess, the merchant asked for a simple reward in return. One piece of rice placed on the first square of a chess board. Then double this on the second square. Double again on the third, etc. By the time you get to the 64th square, there is not enough rice in the world to pay this debt... Thus, I won't be asking about that! However, what about the 16th square?
How much rice would be balancing in the 16th square?
Think you've got the answer?
Check it here
Dr Zonga's Instagram account hits 100 followers. Yeah!
The same day though, a good friend, Oskar, hits 200 followers. Driven by friendly competition (and a little jealousy), Dr Zonga is determined to grow his account.
Assuming:
Dr Zonga's account grows 4% every week.
Oskar's account by 4 followers every week.
Questions
1) How many followers will each account have after 10 weeks?
2) After how many weeks will Dr Zonga have more followers than Oskar?
Think you've got the answer?
Check it here
Oh, and connect on Instagram (@dr_Zonga) to help us hit our target 😉😊.
Walks
As Belgium starts to open up again, new adventures await Dr Zonga. These pictures were taken last Saturday in Dinant, an hour south of Brussels. While walking in Dinant, Dr Zonga set himself a challenge...
Challenge:
Dr Zonga plans to go for a walk every day and he challenges himself to walk 10% further each time.
Assuming:
The walk to Dinant clocked up 7000 metres, and that Dr Zonga managed to walk every day since, except Wednesday (it was raining HARD!), …
Questions
1) How far did Dr Zonga walk on the Thursday?
2) If Dr Zonga got his calculations a little wrong, and he walked 5% more than expected on Sunday, and 6% less than expected on Tuesday, how far did Dr Zonga walk on the Thursday?