Question

Rekha covers certain by car nd she move per hour fastershe would have taken 30 mins lesser time to cover distance if she have moved 2 km hr she would have taken 40 mins more time to cover distance . find the distance in kms


a ) 15
b ) 10
c) 20
D)5
​

Answer 1

Answer:

d 5 km i don't know how to explain this but yeah that is the answer

Explanation:

HOPE IT HELPS

Answer 2

Question :

Choose the correct option :

Rekha covers certain by car. Had she moved 3km per hour faster, she would have taken 30 mins lesser time to cover distance. If she has moved 2 km/hr slower, she would have taken 40 mins more time to cover distance . Find the distance in km.

a ) 15 km

b ) 11 km

c) 20 km

D)5 km

Answer :

Option B.11km is correct.

Therefore the distance is 11km.

Given :

If Rekha had moved 3km per hour faster, she would have taken 30 mins lesser time

If she has moved 2 km/hr slower, she would have taken 40 mins more time.

To find :

The distance travelled by Rekha in km

Solution :

Let the distance = x km and speed = y km/hr

Then,

x/y - x/(y+3) = 30/60

=> (x(y+3) - xy)/y(y+3) = 1/2

=> 3x / y(y+3) = 1/2

=> 6x = y(y+3).......i

Also ,

x/ (y-2) - x/y = 40/60

=>( xy-x(y-2))/y(y-2) = 2/3

=> 2x/y(y-2) = 2/3

=> y(y-2) = 3x..........ii

On dividing eq i by eq ii we get ,

6x /3x = y(y + 3) / y(y-2)

=> 2 = y+3/y-2

=> 2y-4 = y+3

=> y=4+3

=> y = 7

Putting the value of y in eq ii we get,

=> y(y-2) = 3x

=> 7(7-2) = 3x

=> 47-14 = 3x

=> 33 = 3x

Hence, x =33/3

=11

Therefore the distance is 11km.

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