# Difficulty – Medium

Medium difficulty brain teasers and puzzles

## Rebus Puzzle 16

What common word or phrase is this rebus referring to?

``````     SIXTEEN
THOUSAND
FIFTY
NINE
TRILLION
THIRTY``````

#### Solution

Safety in numbers

(“Safety” is spelled out downwards in the numbers listed.)

## Blue and Red Maze

In this maze, you must alternate going through blue and red doors – in other words, you cannot go through two blue doors in a row or two red doors in a row.

Entering through the blue door in the top left, can you find your way through the maze and exit through the red door in the top right?

Continue reading “Blue and Red Maze”

## Rebus Puzzle 14

What common word or phrase is this rebus referring to?

`````` serGeant
geNeral
ensIgn
priVate
colOnel

#### Solution

Moving up the ranks

(Each line is a rank in the military, and “moving” is spelled upwards among the ranks.)

## 3 Digit Code

You have six guesses to figure out a 3 digit code. After each guess, you will be told exactly how many digits are correct but in the wrong place and how many digits are correct and in the right place. You have made these five guesses already:

• 865: exactly one digit in the right place
• 964: exactly one correct digit but in the wrong place
• 983: no correct digits
• 548: exactly two correct digits but in the wrong places
• 812: exactly one correct digit but in the wrong place

What is the correct 3 digit code?

View Solution

## Guess the Number

Jake has a 4-digit number in mind and asks Raj to guess the number. Raj can have 7 guesses, and Jake will give him some hints after 6 guesses.

Raj makes these 6 guesses:

• 6 3 5 8
• 9 3 0 6
• 4 8 8 2
• 6 7 2 8
• 1 1 9 1
• 5 6 2 7

These were all wrong, but Jake says every guess had exactly one (and only one) correct digit in the correct position. Additionally, all the digits are different.

What should Raj’s 7th guess be?

View Solution

## Ants on a Stick

Six ants are walking at 1cm/second on a very narrow stick 100cm long:

• Ant 1: starts at 0, facing right
• Ant 2: starts at 20, facing right
• Ant 3: starts at 30, facing left
• Ant 4: starts at 40, facing right
• Ant 5: starts at 60, facing right
• Ant 6: starts at 80, facing left

When two ants run into each other, they immediately turn around and walk in the other direction.

How long does it take before the last ant walks off the stick?

Continue reading “Ants on a Stick”