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Hello Dear Students.

It was 1997, when I was preparing for my MBA/CAT(2nd attempt  and was a serious attempt. I attempted exactly 144 Ques in CAT. My days CAT used to be a test of 185 Questions. Got A, C, L calls.). That very year, I moved to Delhi(I am from a small town in U.P.) in order to ensure that I get better exposure w.r.to preparations. And 3 days after coming to Delhi, I found a job in Delhi. I started teaching then in Delhi at then number 1 coaching institute for CAT. There I read a poster with some beautiful lines. I copied them and learnt them. Today, when I could not search that old diary of mine, I searched Google and finally found them.

Ques: A 6 digit number is formed by using digits 1.2.3.4.5 & 6. without repeating digits. What is the sum of all such no.s

a)    279999720        b) 299997290                c) 379999720  

d) None of these

Soln: Simple Perm and comb first (to scare you). If a 6 digit number has to be formed using 6 digits (repetition not allowed) then this will be done in 6! Ways (=720, I used scientific calculator to find this out, so better don’t ask me how 720). Let’s take fedcba as a 6 digit number, where a, b, c, d, e, f only represents places and no significance w.r.t values.Now at place a, all the 6 digits 1 to6 can come.

Ques: At what time between 2 and 3 pm, minute hand and hour hand of clock are together?

      a) 2/11 hrs past 2 pm.          B) 2/9 hrs past 2 pm.     C) 2:10 pm     

      d) None.

Soln: Recall what we taught in CLOCKS class. Speed of MH is 6 degree per minute and that of HH is ½ degree per minute. And hence relative speed of MH over HH is 5.5 degree per minute.

Talking about CAT quant section in particular, one topic with maximum number of questions in this section is undoubtedly ‘Remainders’ in Number System. Previously, these questions used to be simple and straight forward with divisors being prime numbers. But now, questions have become trickier with numbers being composite and more importantly bigger.

Now, with each question of CAT, all books and coaching institutes add one paragraph in their books focused on that question. But before seeing that question, none of us know how to start deciphering these questions. One way of solving these questions can be traditional technique (i.e. solving these questions) which is not going to be easy on any given day. But other way can be by using options, which we will try to understand in this article.