Reasoning
In 36 hours, Alex could empty 2 lots of bookshelves, Billie could also empty 2 lots of bookshelves, and Drew could refill 1 lot of bookshelves.
So, 2 + 2 – 1 = 3 lots of bookshelves in 36 hours. Which is 12 hours for one lot of bookshelves.
Alternative Reasoning
Alex and Billie can each empty 1/18 of the bookshelves in 1 hour, but Drew will refill 1/36 of the bookshelves in one hour.
So in one hour we have 1/18 + 1/18 – 1/36 = 1/12.
So it would take 12 hours to empty the bookshelves.
?
Puzzle 2
Starting with a five-letter word, change one letter to create a new word.
This word is then changed by one letter to create another new word.
These words in turn mean:
a gaggle of geesea device for measuring timewhat you can do with a mousea baby chickena device to prevent wheels from movinga surprisea small housea pile of cardsa small piece of woodunable to move
Answers flock = a gaggle of geeseclock = a device for measuring timeclick = what you can do with a mousechick = a baby chickenchock = a device to prevent wheels from movingshock = a surpriseshack = a small housestack = a pile of cardsstick = a small piece of woodstuck = unable to move
?
Puzzle 3
I have a jar of sweets that contains 114 red, 35 blue, 67 green, and 9 yellow.
What chance do I have of picking a yellow sweet with my eyes shut?
Reasoning
Take the third letter of the first word
+ the second letter of the second word
+ plus the first letter of the first word
+ plus the fourth letter of the second word.
