Growing awareness of pollution comes with a side effect: we start using bad language. “PM10,” we say, and add “microns” and “micrograms per cubic metre”. I thought I knew the meanings of those expressions but found out I knew only their definitions. Before working PM10 into “Problematics”, therefore, I had to translate everything into language I could understand. For micrograms per cubic metre, select a square plot of land, a kilometre to a side. Over it, raise a column of air 1 km high; into that, inject a kilogram of pollutants. That’s what some people call 1 μg/m^3, but “a kilo per cubic kilometre” is much easier to picture. [related-post] PM10 is a bunch of tiny killers, defined by their size in “microns”. In simpler language, these air poisoners never grow beyond a 100th of a millimetre in girth. At the smallest end, they have a waist measurement of nearly a 400th part of a millimetre. Smaller than that is another gang, called PM2.5. That’s still too tiny to register, though. Who can imagine what a 400th part of 1 mm looks like? Or even a 100th part? For better visual effect, assume the killers are well-rounded characters (i.e. spheres) and pack them together. It turns out that a cubical box of 1 mm sides — something that will be visible to the naked eye, or at least with specs — can hold between 19 lakh and 12 crore of these little monsters. Finally, here was something I could understand. More importantly, here was the number I could launch your puzzle with. Take 12 crore poisoners of the slimmest out of a cubic millimetre and set them loose in Delhi. Watch them disperse in three directions, North, South and East, where they come under the eye of the respective municipal corps. Now, play with a few numbers. (1) 4.5 crore of the 12 crore little monsters travel North, 6 crore travel South and 7.5 crore travel East. Whenever any of them travels from one region to another, he or she is counted in both those regions. If someone travels everywhere, she or he counts in all three regions. That is why the sum appears to be more than 12 crore. (2) 1.5 crore travel both North and South, 2.4 crore travel both North and East, and 3.3 crore travel both South and East. Puzzle#5A: How many of them travel to all three regions? How many each settle down permanently in North, South and East? What you wrote Two puzzles last week, a number of interesting answers. For those who missed it, Puzzle#4B was a contest based on the key A =1, B = 2. Z = 26. The “value” of a word is the product of its “letter-values” (eg. CAT = 3 × 1 × 20 = 60). As invited, readers contested for the highest possible score from a word of three letters. YUP = 25×21×16 = 8,400. Hope it is correct, keeping my fingers crossed. Anil Kumar Agrawat *** My answer: YUP. Tushar Gupta *** I think the answer is STY (19 × 20 × 25 = 9,500). Waiting for the answer. Lakshmi Swathi Gandham *** ZZZ (a person who is asleep). 26 × 26 × 26=17,576. Anil Kumar (2:17 pm, April 2) *** Good one, Anil, but I must disqualify that. If everyone wrote ZZZ, there would be no contest. Kabir (2:27 pm) *** WRY. 23×18×25=10,350. Anil Kumar (8:05 pm) *** WRY. Anandh Subramanian *** Mr Kabir, I would like to share how I came to find the solution. I opened an Excel sheet. I formatted the first column to list from AAA to ZZZ, and formatted the second column to calculate the products. I then sorted it in descending order of products. Then, I copied to a Word document. Word has a habit of underlining all the non-words in red. The first word with no red underline — WRY — is the word with the maximum score. I can tell you that this is the easiest way to solve this. Sampath Kumar V Unfortunately, Sampath, your easiest way doesn't win you the contest. I too thought WRY gives the best possible score, but Shalesh below had other ideas. The answer is ZUZ = 26×21×26=14,196. A zuz (Hebrew, plural zuzzim) was an ancient Jewish silver coin struck during the Bar Kochba revolt, as well as a Jewish name for various types of non-Jewish small silver coinage, used before and after the period of the revolt. Shalesh Kumar *** The answer could be ZZZ (if comics are anything to go by); or ZUZ. Lakshmi Swathi Gandham Shalesh and Swathi win, the latter's second attempt having come just in time to share the honours. Thanks for enlightening us on the meaning, Shalesh. Finally, let's wrap up Puzzle#4A. It was a really tough one, cracked by only three readers, including regular respondents Tushar Gupta and Sampath Kumar V. The third comes from a first-timer. Boys with 100% — Science: 98; Maths: 150; Hindi: 128; English: 130 Girls with 100% — Science: 90; Maths: 66; Hindi: 47; English: 35. Anandh Subramanian Words, again Puzzle#5B: If someone inhales one of the little monsters you met in Puzzle#5A, you could say that he or she "ATE A CULPRIT". Rearrange those 11 letters to form another description for the killer. A generic, scientific term, a single word. Please send your replies to: kabir.firaque@expressindia.com
