If Deepesh had walked 20 km/h faster he woulh have saved 1 hour in the distance of 60km. what is the usual speed of Deepesh? Pick:
A) 100  B) 299  C) 208  D) 273  E) 222
Explanation:   Let the original speed be x km/h, then   \inline \frac{600}{x}-\frac{600}{(X+20)}=1   \inline \Rightarrow 600\left ( \frac{x+20-x}{x(x+20)} \right )=1   \inline \Rightarrow \: \: x^{2}+120x-12000=0   \inline \Rightarrow \: \: (x-120)(x-100)=0   \inline \Rightarrow \: \: x=100 \: \: and\: \: x=120   \inline \therefore original speed = 100km/h   100nswer: 100
<result>A</result>
If Deepesh had walked 20 km/h faster he woulh have saved 1 hour in the distance of 60km. what is the usual speed of Deepesh?