HTTPS

 If you experience any problems accessing the site using HTTP, you can try HTTPS by clicking the link on the left.

[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 IconKevin and Daniel were rowing their canoe along the River Trent.

In the morning they managed to row upstream at an average speed of 2 miles per hour.

They then stopped for a spot of lunch and a nice rest.

In the afternoon, the pace was a little easier as they were now rowing downstream back to their starting point, and managed an average speed of 4 miles an hour.

The morning trip took them 3 hours longer than the afternoon.

How far did they row upstream?

[Ref: ZOTY] © Kevin Stone

Show Hint Show Answer Print Puzzle
Direct Link: www.brainbashers.com?ZOTY

Answer: 12 miles.

In the morning, rowing at 2 miles per hour, they rowed for 6 hours. In the afternoon, rowing at 4 miles per hour, they rowed for 3 hours.

There are a number of ways of working this out, and here are two of them:

Method 1
If we assume the distance the rowed upstream to be D miles, we know the morning took (D ÷ 2) hours, and the afternoon took (D ÷ 4) hours, with a difference of 3 hours. So:

  D     D     3
  -  -  -  =
  2     4

Multiplying throughout by 2, and then 4, gives:

  4D - 2D = 24

So:

  2D = 24

And:

  D = 12 miles.

They rowed 12 miles upstream.

Method 2
If we assume they rowed for H hours upstream, we know they travelled H x 2 miles in the morning. In the afternoon they rowed for (H - 3) hours, and travelled (H - 3) x 4 miles. We know these distances are the same, so:

  2H = (H - 3) x 4

Giving:

  2H = 4H - 12

Rearranging gives:

  12 = 2H

So:

  H = 6 hours.

They rowed for 6 hours upstream at 2 miles per hour, which is a total of 12 miles.


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