8 thoughts on “Time and Work – 7

  1. a person used a certain number of inlet pipes to fill a particular tank in a certain amount of time.Some time later,he realised that the complete filling up of tank would get delayed by a fourth of scheduled time,so he immediately increases the number of pipe by one third and thus manages to fill tank in time.find percent of tank filled by time number of pipes were increased.

    • Let scheduled time be 100. Then actual time would be 125. We need to save 25. Now by making the number of pipes 4/3, time should becomes 3/4 and if this saves 25 min, that means actual time from then on went from 100 (old) to 75 (new). So, the original pipes were open for 25 min, and would have filled 25/125 = 20% of the tank.

      Alternatively, take total volume of tank as 15 and existing pipes filling 3 per hour (I’m taking numbers which seem suitable. Please don’t ask how I chose these numbers, call it intuition through long practice if you like). So it will take 5 hours actual and should have been done in 4 hours. Now if 3 becomes 4 per hour, then we can do it in 4 hours by 3 + 4 + 4 + 4. So, only the first hour is 3, which fills 3/15 i.e 20%.


  2. Three runners start running simultaneously from different points on a track of length 672 m. A starts from the start line giving B a headstart of 12 m and C a headstart of 24 m. After running for some time they are at the same point. When A covers 224 m, C is 20 m behind B. How far behind A is C, when A reaches the finish line?
    a) 84 m b) 120 m c) 168 m d) 192 m

  3. With just 74 days to Cat 2018, Sir can you please tell me how to go for preparing for DILR section within this limited time and the source for such level of questions to be practiced, I am unable to score more than 60-65 percentile in simcats in this section. Its troubling me a lot.

    • Here’s some basic strategy for DI:


      As for sources, first of all take a fair number of SimCATs (ideally at least 20) and analyse them obsessively to understand the thought process. Build a database of 150+ good sets and the approach for each.

      Also, quite simply the best practice for CAT is CAT itself. So, look at the old CAT papers which had this level of DILR (I would recommend 2006, 2008 and the two slots of 2017 to start, followed by 2005, 2004, 2003 and 2007 if time permits). Again, thorough analysis is imperative.


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