The distance between two places is 200 km. The time taken by moter car to travel from one place to another is more by 2 hrs than the time taken by a zeep car.If the speed of the motor car is 5 kms/hr less than the speed of the zeep car, then find the speed of the motor car.

Explanation

Let the speed of the more car be x km/hr.
`:.` Speed of the zeep car =(x+5) km/hr.
`:.` The time taken by the motor car to travel 200 km is `(200)/(x)` hr and by zeep car it is `(200)/(x+5)` hr.
As per questions, `(200)/(x)-(200)/(x+5)=2`
or, `200((1)/(x)-(1)/(x+5))=2or,200{(x+5-x)/(x(x+5))}=2`
or, `200xx(5)/(x^(2)+5x)=2or,2(x^(2)+5x)=1000`
or, `x^(2)+5x=500or,x^(2)+(25-20)x-500=0`
or, `x^(2)+25x-20x-500=0`
or, `x(x+25)-20(x+25)=0`
or, `(x+25)(x-20)=0`
`:.` either `x+25=0" "or,x-20=0`
`impliesx=-25" "or,x=20`
But speed can not be motor car is `:.x=20`
`:.` The required speed of the motor car is 20 km/hr.