1. Bat $1.05 and ball $0.05. That took me longer than it should've!
2. Five minutes for 100 machines to make 100 widgets.
3. Half the lake would be covered in 47 days.
I used to like these kind of problems when I was at school. I seem to remember one along the lines of...
If tap A can fill a bath in 30 minutes, and tap B can fill the same bath in 45 minutes, and a full bath will empty in 20 minutes if the plug is removed, how long will the bath take to fill if both taps are on and the plug is removed?
...I thought, who on earth would do something stupid like that, but it's a good brain teaser.
solution