#155 Mother Hubbard
Ada Hubbard loves creating riddles and takes every opportunity to pose them. She occasionally includes her daughter Betty in her brain-teasers.
When someone recently asked for Ada and Betty鈥檚 ages, Ada gleefully supplied a riddle instead: 鈥淚 am five times as old as Betty was when I was as old as Betty is now. When Betty is as old as I am now, then I will be 77.鈥�
How old are Ada and Betty?
Solution next week
#154 Party line-up
Solution
There are 10 candidates.
In total, there are 21 鈥渦nits鈥� of the three virtuous traits to distribute among a certain number of people. Since we know, based on Tariq鈥檚 observation, that one trait must be assigned to someone who already has two of them, then we can infer that the other 20 traits are assigned such that each person has two of them. It follows that there are 10 people, nine with two traits, and one with all three.
Quick quiz #139
1 Which type of coal has the fewest impurities: bituminous, lignite or anthracite?
2 The fossil AL 288-1 is better known by what name?
3 The idea that the number of transistors in a dense integrated circuit doubles roughly every two years is known as what?
4 Which organic compound was first isolated in 1838 by French chemist Anselme Payen?
5 What is the theoretical maximum size of a star鈥檚 radius for a given mass called?
Answers
1 Anthracite
2 Lucy or Dinkinesh. The latter translates as 鈥測ou are marvellous鈥� in Amharic, an official language of Ethiopia, where the fossil originated
3 Moore鈥檚 law
4 Cellulose
5 The Hayashi limit