CAT Questions

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As the distance travelled is constant, the time taken is inversely proportional to speed.

Let 'u' be the speed of the current and 'v' be the speed of the boat.

Speed of the boat downstream = v + u & upstream = v - u

=> v+u/v-u = 30/20 => v/u = 5 => v = 5u

=> v + u = 6u = 10/20/60 miles/hr

=> 6u = 30 m/h

=> u = 5 m/h

The western education system was introduced in India by Lord William Bentinck. He is also responsible for a large no of social reforms like the abolition of Sati, infanticide and child marriage.

Sound intensity is measured in decibels(db). Sound pollution above 120 db becomes more hazardous and have adverse affects on human life. 

Let Priyatham's age = x

Then, Vishal's age = 2x; Raghu's age = x/2; Veeru's age = 4x ; Karthik's age = x/4

So, the descending order of ages is :

Veeru > Vishal > Priyatham > Raghu > Karthik

Therefore,  Karthik is the youngest.

Probability of occurrence of an event, 

P(E) = Number of favorable outcomes/Numeber of possible outcomes = n(E)/n(S)

⇒ Probability of getting head in one coin = ½, 

⇒ Probability of not getting head in one coin = 1- ½ = ½, 

Hence, 

All the 11 tosses are independent of each other.

∴ Required probability of getting only 2 times heads =122×129=1211

Let the speed of the stream = x kmph

From the given data,

 129+x+129-x=3 hrs

3x2 = 27

=> x = 3 kmph

Therefore, the speed of the stream = 3 kmph

The given statement implies that 64 Squares on Carrom Board.

Let present ages of Sumit=w, Krishna=x, Rishabh=y and Rohit=z , then
w+x+y = 43x3 = 129 ---(i) and
w+y+z = 49x3 = 147 ---(ii)
Subtracting (i) from (ii), (w+y+z) - (w+x+y)=147 -129 , z- x =18 ---(iii)
Given Rohit's age => z = 54, so from (iii), x = 54-18 = 36