Question

Teerth has to cover a distance of 200 km in 6 hours. In the first 4 hours he travels 122 km

and then rests for 30 minutes. What should be his speed per hour for the rest of the journey

to reach the destination just on time?​

Answer 1

Answer:

Speed of the car =x km /hr

Time taken =t hrs

xt=200

∴t=

x

200

Now, (x+5)(t−2)=200

(x+5)(

x

200

−2)=200

(x+5)(200−2x)=200x

200x−2x

2

+1000−10x=200x

x

2

+5x−500=0

x

2

+25x−20x−500=0

(x+25)(x−20)=0

x=−25,x=20

Speed cannot be negative value, hence, x=20 km/hr