#202 The dating game
Set by Mary Ellis
Every day I play a little game with the date, to keep my mind sharp. The rules are very simple: you take the three numbers that express the date in its simplest form and combine them mathematically in various ways to try to make the numbers 1 to 10.
You are allowed to use the four operations of addition, subtraction, multiplication and division, as well as brackets, square roots and powers. You may use any of these as many times as you want, but you can only use each number in the date once and you have to use all three numbers each time.
My favourite date of 2022 was 16 September (expressed as 16/9/22) because I found a way to make every number from 1 to 10 following those rules, though it took me a while and I used square roots a lot. For example, I found 鈥�1鈥� this way: 鈭�(22 + 鈭�9) 鈥� 鈭�16 = 1.
Can you find a way to get the numbers 2 to 10 with that date?
Solution next week
Quick quiz #182
1 Extant odd-toed ungulates can be divided into three families: Equidae, Rhinocerotidae and what else?
2 Does the hormone leptin increase or decrease appetite?
3 In astronomy, what name is given to the abundance of elements in an object that are heavier than hydrogen and helium?
4 Plants of the genus Ilex are better known by what name?
5 On the geological timescale, what era was the longest in Earth鈥檚 history?
Quick quiz #182
Answers
1 Tapiridae
2 Decrease
3 Metallicity
4 Holly
5 The Palaeoproterozoic era, which spanned 900 million years, from 2.5 billion years ago until 1.6 billion years ago