October 2012







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Here is an old puzzle that has not lost its shine.

I have to attend an urgent meeting in an hour's time. I have 45 minutes to get ready and leave home to be in time for the meeting.

But I do not have any clocks, watches or any other gadgets to measure time. Wait! I do have two ropes that have a peculiar characteristic. Each of these ropes, when lighted at one end, will burn up completely in one hour. However, the ropes do not burn at a uniform rate. Thus, one of the ropes when lighted at one end, may take 45 minutes to burn through half the length but may take just 15 minutes to burn the remaining half. Same is the case with the other rope as well. The two ropes are available with me and I have a matchbox as well. How do I measure 45 minutes?







Click here for the solution

Some useful links for
your career:


  • Union Public Service Commission - www.upsc.gov.in
  • IIT-Kharagpur - www.iitkgp.ac.in
  • Indian Statistical Institute - www.isical.ac.in
  • Indian Institute of Technology Madras - www.iitm.ac.in
  • Indian Institute of Management, Ahmedabad - www.iimahd.ernet.in
  • Indian Institute of Mass Communication - www.iimc.nic.in
  • IIT Bombay - www.iitb.ac.in
  • Indian School of Mines, Dhanbad - www.ismdhanbad.ac.in
  • Birla Institute of Technology, Ranchi - www.bitmesra.ac.in
  • Central Institute of Fisheries Nautical and Engineering Training - www.cifnet.nic.in
  • Indian Institute of Information Technology, Allahabad (Deemed University) - www.iiita.ac.in
  • Central Marine Fisheries Research Institute, Kochi - www.cmfri.com
  • Tata Institute of Social Sciences, Mumbai - www.tiss.edu

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