Riddles, one at a time
Five Weekends
What day of the week is the 1st?
How many days must the month have for 3 days of the week to come 5 times?
Friday
31 days = 4 weeks + 3 days, and those 3 extra days start the month: Friday, Saturday, Sunday.
Sun Gate to Moon Gate
Fewest days from sun to moon?
13 DAYS
Two oases then a tower: 3 + 5 + 2 + 3 = 13.
Fewest Tokens: Pay 14
Which tokens pay 14 with the fewest tokens?
Biggest first is not always fewest. Try every pair.
7 + 7
Just 2 tokens. Biggest first, 10 + 1 + 1 + 1 + 1, needs 5.
Fence Posts
A straight 15 m fence has a post every 3 m, with one at each end. How many posts are there?
Count the gaps first, then the posts.
6
15 ÷ 3 = 5 gaps, and 5 gaps need 6 posts.
Lighthouse Flashes
A lighthouse flashes evenly. From the 1st flash to the 6th takes 5 seconds. How long from the 1st flash to the 11th?
Count the gaps between flashes, not the flashes.
10 seconds
Flash 1 to flash 6 is 5 gaps, so each gap is 1 second. Flash 1 to 11 is 10 gaps.