CAT Questions

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Optical fiber works on the principle of total internal reflection.

The Total Internal Reflection is the phenomenon in which the complete reflection of a light ray reaching an interface with a less dense medium when the angle of incidence exceeds the critical angle.

The given figure can be labelled as :

The simplest triangles are AJF, FBG, HDI, GCH and JEI i.e 5 in number.
The triangles composed of the three components each are AIC, FCE, ADG, EBH and DJB i.e 5 in number.
Thus, there are 5 + 5 = 10 triangles in the given figure.

A book has a spine to hold all the pages, but it has no bones.

Total cost of 4 cars =  1+2 = 3 lakh

Total S.P of 4 cars = 3 x 1.5 = 4.5 lakh   (Since S.P = 100 + Gain%100 x C.P)

 S.P of 1 car = 1.2 lakh 

S.P of rest 3 cars = 4.5 - 1.2 = 3.3 lakh

 Average S.P of all the 3 cars = 1.1 lakh

Part filled by (A + B) in 1 minute = (1/60 + 1/40) = 1/24
Suppose the tank is filled in x minutes.
Then, x/2(1/24 + 1/40) = 1
(x/2) * (1/15) = 1 => x = 30 min.

Observe that in each column, square of sum of digits in the first row = Respective second row elements.

In the same way, square of sum of digits in the second row = Respective third row elements.

=> 6+42=102=100

=> 4+92=132=169

=> 8+12=92=81.

Let the time taken by train be 't' hrs.

Then,

40t = 35t + 1560

40t = 35t + 35/4

t = 7/4 hrs

Therefore, Required length of the total journey d = s x t

= 40 x 7/4

= 70 kms.