[OK]

Privacy Policy  -  Terms & Conditions  -  See Details
This website uses cookies. By using this website you are accepting the use of cookies.
For more information please view our privacy policy.

BB Logo
Spacer
Line
Line

Difficulty: EasyPuzzle Details

Puzzle IconIn farmer Brown's hay loft there are a number of animals, in particular crows, mice and cockroaches.

Being bored one day, I decided to count the animals and found there were exactly 150 feet and 50 heads in total, and there were twice as many cockroaches as mice.

How many of each animal were there?

[Ref: ZVYU] © Kevin Stone

Show Hint Show Answer Print Puzzle

Answer: 10 cockroaches, 5 mice and 35 birds.

Cockroaches have 6 feet, mice have 4 and birds have 2.

For every mouse there are two cockroaches, so every mouse is worth 3 heads and 16 feet (4 + 6 + 6).

We can now write down an expression for the heads and the feet (calling birds B and mice M):

Heads gives us:
   B +  3M = 50       (1)
Feet gives us:
  2B + 16M = 150      (2)

If we double (1) we get:

  2B +  6M = 100      (3)

We can now do (2) - (3) to give:

        10M = 50
          M = 5
So we have 5 mice (and 10 cockroaches). We can use M = 5 in (1) to give:

  B + 3 x 5 = 50
     B + 15 = 50
          B = 35

So, C = 10, M = 5 and B = 35. Checking that 10 + 5 + 35 = 50, and 10 x 6 + 5 x 4 + 35 x 2 = 150.


Our Favourite Illusions

 Shadow Illusion
Are the squares A and B the same colour?

 Spinning Dancer
Which way is the dancer spinning?

 Impossible Waterfall?
Is the water flowing uphill in this impossible waterfall?

 The Butterfly
A colourful butterfly?

 Duck Or Rabbit?
Is this a duck or a rabbit?

 Hidden Faces
Can you find his three daughters as well?

 Blind Spot
An amazing demonstration of your blind spot.

 Impossible Prongs?
Impossible prongs?

 What Am I?
Can you tell what this is a picture of?

 Who Turned To?
Who is missing?

 Same Eyes?
Are her eyes the same colour?

 Parallel Cafe Wall Lines?
Are the horizontal lines parallel?

 



 

Line


BrainBashers™ is a trademark. This website uses cookies. By using this website you are accepting the use of cookies. For more information please view our privacy policy. By using this website you are also agreeing to our terms and conditions.

Line
Line