You may also like

Fixing the Odds

You have two bags, four red balls and four white balls. You must put all the balls in the bags although you are allowed to have one bag empty. How should you distribute the balls between the two bags so as to make the probability of choosing a red ball as small as possible and what will the probability be in that case?

Scratch Cards

To win on a scratch card you have to uncover three numbers that add up to more than fifteen. What is the probability of winning a prize?


At Holborn underground station there is a very long escalator. Two people are in a hurry and so climb the escalator as it is moving upwards, thus adding their speed to that of the moving steps. ... How many steps are there on the escalator?

Tree Tops

Age 14 to 16
Challenge Level

Tree Tops printable sheet

Imagine you have a large plot of land ideal for planting a forest.

First you plant the trees...
Click below to find out the costs of planting.


Terry's Trees

For all your planting needs

We bring the saplings and do all the planting so you don't have to! 

Sitka Spruce £120 000 per hectare
European Larch £115 000 per hectare
Lodgepole Pine £130 000 per hectare 

Give us a call and we'll do the rest!


Then, after 10 years, the forest is thinned to give the remaining trees more room to grow.
The forest needs to be thinned again after another 10 years.

The wood from the thinning is sold. Click below to see the rates.

Theo's Thinning Company

Got a forest that needs thinning? Call Theo!
We pay the best rates:
  10 year thin* 20 year thin*
Sitka Spruce 10 40
European Larch 15 40
Lodgepole Pine 20 30
*All values quoted are thousands of £ per hectare


Finally, the time will come when you cut down all the trees in the forest and sell the timber. You might decide to do this 30 or 40 years or even longer after first planting your trees! Nobody said this was a "get rich quick" scheme...

Click below to see how much profit you will make from selling your timber, depending on when you choose to cut down your trees.

Lou's Lumber

Got a forest you no longer need?
We can cut it down!

Whether your trees are 30 years old or 100 years old, we will pay the best prices.

Check the table below for our rates.
Age of Forest
30 358 192 123
40 513 469 366
50 693 858 646
60 834 1184 950
70 1127 1158 1144
80 904 1059 1311
90 805 837 1476
100 666 783 1360
All prices are quoted in thousands of £ per hectare.

What strategy will maximise the profits for you and your family in the decades to come?

Here are some questions you could consider


  • Which tree should you choose to minimise the cost of planting the forest?
  • Which tree should you choose to minimise your loss after 20 years?
  • What would the profit be for each type of tree after 30, 40, and 50 years?
  • What happens to the prices paid for each type of wood over the 100 year period? Why might this be the case?

What's the maximum profit you could make after 100 years?