IIFT 2019 Question Paper | Quants

CAT Questions

The best way to boost your IIFT prep is to practice the actual IIFT Question Papers. 2IIM offers you exactly that, in a student friendly format to take value from this. In the 2019 IIFT, quants were a mixed bag of questions of varying difficulty, with some routine questions and the others were very demanding. Some beautiful questions that laid emphasis on Learning ideas from basics and being able to comprehend more than remembering gazillion formulae and shortcuts.

Question 1 : You travel by Delhi Metro every day from Botanical Garden, Noida to Hauz Khas, Delhi. At Hauz Khas metro station, you use an escalator to get out of the station. The escalator takes 80 seconds. One day, the escalator was not working and you walk up the escalator in 50 seconds. How many minutes does it approximately take you to walk down the working escalator?

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Video Explanation

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Explanatory Answer

We see that the time given in the question is for the person going up the escalator without him walking on it, and the time taken by the person walking without the escalator. This makes thing simpler!
Let T_e be the time taken by the escalator. T_e=80s
Let T_p be the time taken by the person. T_p =50s

So, the ratio of speeds of the escalator to the person will be Se : Sp :: 5x : 8x
Since the person is walking up the escalator moving down, the net speed of climbing will be the difference in the speeds of the person and the escalator = 3x.

We know that speed is inversely proportional to time.
So,
With 5x speed 80s time is taken
We can say for 3x speed \\frac{80*5x}{3x}) time will be required
=\\frac{400}{3}) ≈ 2.2 minutes

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The question is "How many minutes does it approximately take you to walk down the working escalator?"

Hence, the answer is, "2.2 minutes"