Each month, a new set of puzzles will be posted. Come back next month for the solutions and a new set of puzzles, or subscribe to have them sent directly to you.



Feedback
There are more than one way of doing these puzzles and may well be more than one answer. Please let me and others know what alternatives you find by commenting below. We also welcome general comments on the subject and any feedback you'd like to give.
If you have a question that needs a response from me or you would like to contact me privately, please use the contact form.
Get more puzzles!
If you've enjoyed doing the puzzles, consider ordering the books;
 Book One  150+ of the best puzzles
 Book Two  200+ with new originals and more of your favourites
Both in a handy pocket sized format. Click here for full details.
Last month's solutions

Solution: Since Gear A has 20 teeth and Gear B has 60 teeth, the gear ratio for Gears A and B is 20:60. Thus the ratio of the number of revolutions per minute (rpm) for the two gears is 60:20, or 3:1. Similarly, since Gear B has 60 teeth and Gear C has 10 teeth, the gear ratio for Gears B and C is 60:10, and the ratio of the rpms for the two gears is 10:60. Therefore, if Gear A turns at 100 rpm, then Gear B turns at 100/3 rpm, and


Solution: Since angle ABC (x°) = 100°; then angle BCA = 180° – 100° – 20° = 60°. 
Solution: Let x represent the number of days the second voyage lasted. The number of days the first voyage lasted is then x + 43. 