Browsing archives for 'Logic'

Family Crossing

Logic 8 September 2010 21 Comments

Today’s puzzler is from Borrow-A-Geek:
There are two sons and a dad, a row boat and a river to cross.
Each son weighs 75lbs
The dad weighs 150lbs
The row boat capacity is 150lbs
They all need to get accross the river, how can they do this with out ropes or any fancy tricks?

Someone Take This Shovel Out Of My Hands

Logic 10 August 2010 10 Comments

From Julio Sepia:
It takes one day for ten workers to dig ten holes.
It takes two days for five workers to dig ten holes.
How much does it take for one man to dig HALF a hole?

Desert Tracks

Logic 27 July 2010 14 Comments

From Andreas Renberg:
A large caravan is stuck in the desert. They have enough food and water to last them a while, but still need to send someone to find help.
The nearest city is a 7 day journey, but each person is only able to carry 4 days worth of food.
What do they do [...]

Which Switch?

Logic 20 July 2010 27 Comments

From Sean Murphy:
There are 1000 switches numbered from 1 to 1000. They are all off. I begin by flicking all the switches. I then flick every second switch (2,4,6…). I then flick every third switch (3,6,9…). I repeat the process 1000 times.
How many switches are off by the time I have finished?

Lie Detector

Logic 13 July 2010 18 Comments

From fretje:
When you die, you go to this place where there are two doors: one goes to heaven, the other one goes to hell. There’s a guard in front of each door. You don’t know which door is which. The only thing you know is that one of the guards is always telling the [...]

Bomb Planning

Logic 6 July 2010 18 Comments

From asas:
You have two 4 min fuses and a bomb. You want to be able to time the detonation of the bomb for 1min. Like the ropes puzzle, neither fuse burns at a uniform rate throughout.
How do you time your act of senseless destruction?

Circular Quarters

Logic 22 June 2010 15 Comments

You are playing a game with your friend sitting across a perfectly round tabletop. You each have a supply of quarters which you will place on the table one at a time, without moving any other quarters and without overlapping. The last person who successfully puts a quarter on the table without running [...]

Burning Ropes

Logic 17 June 2010 37 Comments

You have a large selection of ropes of varying lengths. The ropes burn at different rates, even one part of a rope may burn differently than another part, but there’s no way to tell just by looking at them. What you do know is that every single rope will take exactly 1 hour [...]