Question

A student can reach the exam centre from his house in 10 hours. If he reduces his speed by 1/20th, he will cover 10 km less in that time. Find the distance of exam centre from his house.
a)100
b)200
c)150
d)250

Answer 1

It goes like this :

Let the speed of the student be x kilometers per hour.

Then :

Distance of exam centre from school = (x*10) kilometers ( By using formula, distance = speed * time )

Now , new speed = x - x/20

= (20x - x)/20

= 19x/20

Finally , our equation which will give us the value of x :

19x/20 *10 = 10x - 10

19x/2 = 10x - 10

19x = 2(10x - 10)

19x = 20x - 20

x = 20

Since x is the speed of the student :

Distance = Speed * Time

= (20*10) kilometres

= 200 kilometers

Hence , the distance between the student's house and exam centre is 200 kilometres

So according to the question,the correct answer should be option (b) .

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