Question

to cover 14 kilometre distance Anubhav cycles at a certain average speed if he reduces average speed by 1 kilometre per hour takes 20 minutes to more to cover the same distance find the original speed​

Answer 1

7 km/hr

Step-by-step explanation:

let his original speed be x

distance /speed = time

14/(x - 1) - 14/x = 20/60 hr

14/ x(x- 1) = 1/3 => x^2 - x - 42 = 0

x^2 - 7x + 6x - 42 = 0

x(x - 7) + 6( x - 7) = 0 => x =7,- 6

speed can't be-ve so neglect - 6 hence,original speed = 7 km/hr

Answer 2

Answer:

7 km/hr

Hope you got your answer.. Thank You..

Step-by-step explanation:

Let, the original speed x km/hr

We know that Time = Speed / Distance

So, time to cover 14 km distance at original speed = 14/x hr

When the average speed reduce by 1 km/hr, speed will be ( x-1) km/hr

Now, time to cover 14 km distance = 14/ (x-1) hr

Equation,

14/(x-1) - 14/x = 1/3 [20 min = 20/60 hr = 1/3 hr]

or, (14x-14x+14)/x(x-1) = 1/3

or, 14/(x^2-x) = 1/3

or, x^2-x=42

or, x^2-x-42=0

or, x^2-(7-6)x-42=0

or, x^2-7x+6x-42=0

or, x (x-7) + 6 (x-7)=0

or, (x-7)(x+6)=0

After, Solving the equation value of x = 7 or x=-6

But, as the speed never be negetive, so the value of x is 7

so, the original speed is 7 km/hr