#174 Pieces of eight
I have a 12-hour digital number display alarm clock. As is normal on digital clocks, each of its four digits is constructed using seven possible segments.
I go to bed when the display is at its dimmest and awake when it is at its brightest.
How long am I in bed?
Solution next week
#173 Knight moves
Solution
Knight 618, Bishop 591.
Call the knight鈥檚 numbers BCD and ABCD, and the bishop鈥檚 numbers XYZ and AXYZ. Number AB must be different from AX because the knight and bishop can鈥檛 type the same consecutive digits. This means YZ must be high enough that adding 27 increases the hundreds digit. Since there is no zero on this number pad, the only option is that Y = 8 or 9 and C = 1. Since C = 1, B and D must be either 6 or 8, the two numbers we can reach from 1 in a knight move. This gives us four possibilities to check: 616, 618, 816 and 818. Subtracting 27 from each of them, we find 618 鈥� 27 = 591 is the only number that can be made by a bishop. I could also put a 1 or a 7 at the front to make the knight numbers 1618 or 7618, both 27 more than a bishop number.
Quick quiz #158
1 Siphonophores are colonial organisms that are each made up of several genetically identical animals. What are these individual organisms known as?
2 In what year was the last solar maximum, the period in which the sun is most active?
3 What name is given to a widespread, straight-line storm with destructive winds, often associated with the US?
4 Where in the human body would you find the canthi?
5 The extinct shark Megalodon鈥檚 name translates to what?
Answers
1 Zooids
2 2014
3 Derecho
4 The eye 鈥� they are the corners where your eyelids meet
5 鈥淏ig tooth鈥�