# Brain Teasers and Puzzles

## Puzzle Details

River Log - Logic Puzzles

One fine morning twelve intrepid travellers found themselves facing a rather large river that they had to cross.

Luckily there was a log that they could use to cross the river, but only if they crossed in single file.

Can you figure out who crossed first (and the order in which they all crossed)?

Note: since they crossed from left to right, the first person to cross is on the right, and the last person to cross is on the left.

The names of the travellers were: Alex, Ashley, Blake, Chris, Jessie, Emery, Logan, Quinn, Riley, Ray, Sam, Taylor.

1. Sam got on the log three people later than Chris. Chris got on two people after Logan.

2. Ray got on the log two people earlier than Emery, who got on two people earlier than Logan, who got on three people earlier than Riley. Ray was not the first one on the log.

3. Alex got on the log two people after Quinn.

4. Blake got on three people before Quinn.

5. Jessie got on the log two people before Taylor. Jessie was not the first one on the log.

6. Taylor got on just after Emery.

They crossed in the following order (first is on the right):

Alex, Sam, Quinn, Riley, Chris, Blake, Logan, Taylor, Emery, Jessie, Ray, Ashley.

Starting with Clue 2, we can place Ray, Emery, Logan and Riley as follows:

Riley, -, -, Logan, -, Emery, -, Ray, -

Clue 6 tells us that Taylor got on just after Emery, giving us:

Riley, -, -, Logan, Taylor, Emery, -, Ray, -

Clue 5 tells us that Jessie got on two people before Taylor, giving us:

Riley, -, -, Logan, Taylor, Emery, Jessie, Ray, -

By Clue 1, Chris got on two people after Logan, giving us:

Riley, Chris, -, Logan, Taylor, Emery, Jessie, Ray, -

And Clue 1 also tells us about Sam, giving:

Sam, -, Riley, Chris, -, Logan, Taylor, Emery, Jessie, Ray, -

We now have a line of 11 people, the missing person is either in front of Ray, or behind Sam.

The only way to place Alex, Quinn and Blake using Clue 3 and Clue 4 is if the missing person is behind Sam giving:

-, Sam, -, Riley, Chris, -, Logan, Taylor, Emery, Jessie, Ray, -

And therefore we can now place Alex, Quinn and Blake as follows:

Alex, Sam, Quinn, Riley, Chris, Blake, Logan, Taylor, Emery, Jessie, Ray, -

But who crossed first?

The only person we've not yet found a space for is Ashley. So Ashley crossed first.

Alex, Sam, Quinn, Riley, Chris, Blake, Logan, Taylor, Emery, Jessie, Ray, Ashley.