#58 Lego lockdown
It is lockdown in my house and to keep the kids occupied, I have challenged them to find all the possible sequences when placing red 1脳1 and blue 2脳1 Lego blocks in a row.
There is only one way of making a row of length one (one red); there are two ways of getting a row of length two (B or RR); and three ways of getting a row of length three (BR, RB and RRR).
But after length three, the pattern seems to break down. There are five ways to get length four (BB, BRR, RBR, RRB and RRRR).
I鈥檝e now set the kids the task of finding how many ways there are of making a row of length 10. That should keep them busy. But their further challenge is to work out the pattern, so they can figure out the number of sequences for any length of row. Can you help?
Answer next week
#57 Matchstick magic
Solution
The 11 possible calculations that yield an odd number are: 8-3, 3脳9, 6+3, 9+2, 9-0, 9-6, 6+5, 5+0, 0+5, 8-5 and 5+6
Quick quiz #50
1 What letter is missing from this list: m, k, s, a, c, m?
2 What is the hexadecimal number 3E8 in decimal notation?
3 In 1999, Eileen Collins became the first woman to perform what role that required her to have flown jet aircraft for at least 1000 hours?
4 How many bytes are there in a kibibyte?
5 Why did a small cylinder of platinum-iridium alloy held in the Pavillon de Breteuil in Saint-Cloud, France, lose its lustre in 2019?
Answers below
Quick quiz #50
Answers
1 Another k: these are the initials of the seven SI base units, metre, kilogram, second, ampere, candela, mole, kelvin
2 1000
3 Command a space shuttle mission
4 1024, or 210; this was the original definition of a kilobyte
5 It ceased to be the international prototype kilogram, used to specify this unit of mass. It was replaced by a specification based on fundamental physical constants