Door to doer logic

Pencil impressions are superficial, in the sense that they do not percolate into the bottom layers of paper.

E4
It's come to my knowledge that when I run your email IDs and your names, they're unfortunately also available to Net phishers. Now I know this is neither your fault nor mine, but it still happens, and some of you have complained that you're suddenly getting a whole hog of spam. My solution is, if you think email exposure is interfering with your online incarnation then, in future, just let me know where your city is and I'll just run that instead. Fair enough?
Right, back to business. Supposing you're now suddenly the chief honcho of five alphabetic employees named A, B, C, D and E, whose jobs (not necessarily respectively) are Door Opener, Door Shutter, Doorknob Polisher, Bottle Washer and Welfare Officer. And this is a copy of the rules you've put up on the notice board: (1) C is to get 10 per cent more than the worst paid of all of you. (2) A is to be paid more than D. (3) The Bottle Washer is to get 5 per cent more than 10 per cent less than B. (4) D is to get either one buck more or one buck less than E. (5) The Door Opener's wages are to be an odd multiple of 10 sucks (100 sucks = one buck). (6) E is to get 20 per cent more than one buck less than the Doorknob Polisher. (7) The Door Shutter is to be the best paid of you lot. (8) Your wages are all to be different and each one is to be a multiple of 10 sucks. (9) No one is to get more than 20 bucks or less than 10 bucks per week.
So what are going to be their weekly wages unless, of course, you want a revolt up in your un-unionised arms?
DEAR MS
(The problem was: "What is the funda behind the erasing action of an eraser? That is, why can't a pencil eraser erase pen marks also?" - MS)
Lead-Kindly-Light Dept:
Pencil impressions are superficial, in the sense that they do not percolate into the bottom layers of paper. An eraser removes pencil writing when the rubber in the eraser physically sticks to the lead/graphite on the page and removes it and, in the process, rubs itself off the eraser. This is not possible with ink as the ink seeps into the bottom layers of the page. When continuously erased, the ink comes off along with the paper layers and leaves a hole in the page.
K Sundaram, sunooty@yahoo.com
A pen produces ink marks on paper. The ink wets the paper and then gets absorbed. So, dry white paper turns into dry coloured paper. Since paper reacts with ink, the pigments can't be removed. Pencil marks are dark lines of graphite that don't react with paper. So erasers erase pencil marks due to the scrubbing force.
Krishna, krishp84@gmail.com
64-Squares Dept:
(Regarding the two chess problems:) 1. For a rook, it takes a minimum of 18 moves to cover all the squares, when it starts from one of the central four squares (with paths overwritten). 2. There are a total of 9C2x9C2 = 1,296 four sided figures (both rectangles and squares). Out of these, there are 64 unit squares (of size 1x1), 49 squares of size 2x2, 36 squares of size 3x3 . . . 1 of size 8x8. So a total of 1 + 4 + 9 + . . . + 64 = 204 squares and hence 1296 - 204 = 1,092 rectangles.

• Chandrasekhar Karri, karri.kmds@gmail.com
  

Sub-Urban-Dictionary Dept:
 
I saw the solution posted by Alan D'Souza in the column last week. However, the given six words do not contain a U and therefore the word STUPID cannot be made from those letters. If, however, the word STIPID is used instead of STUPID, the magic square works. As for the validity of the word STIPID, see this: Urban Dictionary - "Stipid. the superior and far more intense form of stupid. You're so stupid, you're not even stupid - you're stipid".
K T Rajagopalan, ktremail@gmail.com
ENDGAME(S)
 
- (Submitted by Dr Vinayak Shukla, shukla58@hotmail.com)
(To get in touch with Mukul, mail him at mukul.mindsport@gmail.com)

• Mindsport