The Israeli education minister, Yuli Tamir, also the chairperson of the Wolf Foundation Council, has announced that the 2007 Wolf Prize in Mathematics, shall be awarded to Prof. Harry Furstenberg of the Hebrew University, Jerusalem. According to Tamir, Furstenberg has been chosen “for his profound contributions to ergodic theory, probability, topological dynamics, analysis on symmetric spaces and homogenous flows.” The late German-born inventor, diplomat and philanthropist, Dr Ricardo Wolf, had established the Israel-based Wolf Foundation.

Five annual prizes of $100,000 have been awarded each year since 1978. The prizes are awarded in five different fields to outstanding scientists and artists “or achievements in the interest of mankind and friendly relations among peoples.” Till date, a total of 232 scientists and artists from 22 countries have been honoured.

In a wood-cutting factory, four large sawing machines stand in a windowless room. Each machine has an on/off switch attached, there being no doubt as to which switch controls which machine. Outside the door to the room are four back-up on/off switches, one for each machine inside. The power for each machine must first pass through the back-up switch, and then the machine switch before reaching the saw. The problem is the new manager cannot decide how these back-up switches match with the machines inside the room. One day, the manager’s brother visits. The manager takes him inside the sawing room where all four machines are at work and explains the problem. The brother announces that he intends to leave the room and that when he returns he will be able to match correctly the four switches outside the room to the four machines inside. The brother works alone, cannot see the machines from outside the room and solves the problem purely by operating switches. How is it possible? (BRC)

Solutions on February 12

CORRECT ENTRIES

January 15

Rimi Khemka, Calcutta; Mausam Kanjilal, Howrah; Souvik Roy, Howrah; Sayonil Mitra, Shantiniketan; SPS Jain, Noida; Conan Mukherjee, Calcutta; Gokul Panigrahi, Calcutta; Joshua Varghese; Deepti Bansal, Midnapore; Sourabh Choraria, Calcutta; Puneet Kandoi, Hooghly; Debasish Jana, Calcutta; Subrata Kumar Chatterjee, Calcutta; Vineet Bhansali, Delhi; Sayan Chattopadhyay, Delhi; Durga Pandey, Howrah; Bandana Srivastava, Noida; Chandana Barua, Calcutta, Satarupa Dasgupta, Silchar, Koel Ganguly, Calcutta, Saba Nadvi, Ranchi, Jasmeet Kaur, Calcutta

Please send in your entries to knowhow@abpmail.co, within 10 days. Do not forget to mention the date of the puzzle in the subject line. For snail mail the address is KnowHow, The Telegraph, 6, Prafulla Sarkar Street, Calcutta — 700 001

PUZZLE CRACKED

The solutions to the puzzles (January 15) are — Solution 1: In order to guarantee a win, you should place your piece in the geometric centre of the board. Now, wherever your opponent places his next piece, you can place yours directly opposite, so that the pieces are symmetrically aligned. You will be able to repeat this tactic until no space is left on the board for your opponent, at which point you win the game.

Solution 2: There were 3,000 gold coins, 4,000 silver and 5,000 bronze. Assume each statement to be true in turn and examine the consequences. If Dimwit is not lying, there are 3,000 silver coins, 5,000 bronze coins and 4,000 gold coins. However, this would make Beefbrain’s statement true. Logically, if Beefbrain is truthful, so is Dimwit. Only if Thickplank is honest are the other statements false.