Brilliantly done, as always!
(Assuming, of course, you have taken the trouble to be expert in calculations 😀 )
Please come up with the set of “Naya-Purana mixer grinders” from CAT 2004.. I get stuck whenever I try that 😦 Should similar sets be left alone under the exam conditions?
Fantastic way of solving. As you have come up with the way of faster calculation why dont you write any article about approximation.
That will be seriously helpful for such problems.
Harsh, my techniques are pretty hard to explain/convey even in person 🙂 They basically depend on a very solid feel for numbers, gained through playing with them a lot. I am not sure if it is even possible to demonstrate them in a video form… will think it over, however, and make a post if I can. No promises 🙂
Kingsly, it is always easier for me (after the fact) to go “cruise control” when I am demonstrating/explaining 🙂 So please don’t take it too much to heart. I spend a little while on each set trying to think of the best way to explain it. If I face something like this in the actual exam, I might not immediately see this particular approach. But I will start with the assumption that for most sets there will be a reasonable approach, and will therefore look for one. Chances are I will find something at least half as good, as long as I am willing to look 🙂 Remember that even if it takes ten minutes instead of five, 9 marks in ten minutes is a perfectly acceptable return. And remember that most sets (especially the calculative ones!) are probably not nearly as scary as they appear at first.
Part of the reason I am doing these sets is that too many of my students get back to me saying something like “the DI looked so intimidating that I didn’t even try it” and so I am trying to demonstrate that if you hit upon the right approach, these very sets were perfectly doable. And the same will probably hold good on the day of your exam.
Assuming that in the new pattern there will be around 15 questions of DI, you can’t ignore them sight unseen. Maybe one or two sets might be really rough, but totally leaving out 15 % of the paper on the assumption that “mujhse DI nahin ho payega” is asking for trouble, I feel…what say?
CAT-holics 
Hi J,
Brilliantly done, as always!
(Assuming, of course, you have taken the trouble to be expert in calculations 😀 )
Please come up with the set of “Naya-Purana mixer grinders” from CAT 2004.. I get stuck whenever I try that 😦 Should similar sets be left alone under the exam conditions?
Regards 🙂
Harsh
Yes that is a nice set 🙂 Will try to do it soon if I can – right now am working on some sets from 2005 and 2008, 2004 had some mazedaar sets too…
regards
J
Hello J,
Fantastic way of solving. As you have come up with the way of faster calculation why dont you write any article about approximation.
That will be seriously helpful for such problems.
Thanks
Harsh, my techniques are pretty hard to explain/convey even in person 🙂 They basically depend on a very solid feel for numbers, gained through playing with them a lot. I am not sure if it is even possible to demonstrate them in a video form… will think it over, however, and make a post if I can. No promises 🙂
regards
J
wow…i totally screwed this up royally during the exam…i feel like a dud after watching you go all cruise control over this problem… :disappointed
Kingsly, it is always easier for me (after the fact) to go “cruise control” when I am demonstrating/explaining 🙂 So please don’t take it too much to heart. I spend a little while on each set trying to think of the best way to explain it. If I face something like this in the actual exam, I might not immediately see this particular approach. But I will start with the assumption that for most sets there will be a reasonable approach, and will therefore look for one. Chances are I will find something at least half as good, as long as I am willing to look 🙂 Remember that even if it takes ten minutes instead of five, 9 marks in ten minutes is a perfectly acceptable return. And remember that most sets (especially the calculative ones!) are probably not nearly as scary as they appear at first.
Part of the reason I am doing these sets is that too many of my students get back to me saying something like “the DI looked so intimidating that I didn’t even try it” and so I am trying to demonstrate that if you hit upon the right approach, these very sets were perfectly doable. And the same will probably hold good on the day of your exam.
Assuming that in the new pattern there will be around 15 questions of DI, you can’t ignore them sight unseen. Maybe one or two sets might be really rough, but totally leaving out 15 % of the paper on the assumption that “mujhse DI nahin ho payega” is asking for trouble, I feel…what say?
regards
J