#15 Domino strips
Set by Peter Rowlett
There are three ways to cover a 3 脳 2 grid with dominoes.
How many ways are there to cover a 4 脳 2 grid? What about a 6 脳 2 grid?
Can you find a pattern that would help you work out the number of different ways dominoes can be used to cover any n 脳 2 rectangle?
Solution next week
#14 Factor graphs
Solution
Here鈥檚 a factor graph of 1-10:
You can connect every number up to 14, but adding 15 requires drawing lines to 3 and 5, which leads to crossing. If we exclude 1, you can add every number up to 23 (see below 鈥� some prime numbers now require no lines), but 24 has too many factors.
Quick quiz #247
set by Bethan Ackerley
1 The temperature above which certain materials lose their permanent magnetic properties is named after which scientist?
2 The doughnut-shaped belts of radiation surrounding Earth are named after which physicist?
3 What name is given to the dividing groove down the middle of the tongue?
4 The Hayabusa mission, launched in 2003, brought back material from which asteroid?
5 On which island would you find Mount Tambora, which in 1815 was the site of one of the largest volcanic eruptions in recorded history?
Quick quiz #247
Answers
1 Pierre Curie
2 James Van Allen
3 The median sulcus
4 Itokawa
5 Sumbawa, Indonesia
Article amended on 17 May 2024
We have corrected the diagram for the solution to BrainTwister #14