Question

Jayvee is riding on an electric bike covers a distance of 30 km in a direction of the wind and comes back to his original position in 6 hours. If the speed of the wind is 12 km/hr. Find the speed of the electric bike.​

Answer 1

Answer:

Jayvee is riding on an electric bike covers a distance of 30 km in a direction of the wind and comes back to his original position in 6 hours. If the speed of the wind is 12 km/hr. Find the speed of the electric bike.

Answer 2

Given: Jayvee is riding on an electric bike that covers a distance of 30 km in a direction of the wind and comes back to his original position in 6 hours. The speed of the wind is 12 km/hr.

To find: The speed of the electric bike.​

Solution:

• Let the speed of the electric bike be equal to x.
• The formula of speed is given as,

        $s = \frac{d}{t}$

• Here, s is the speed of the electric bike, d is the distance covered by it and t is the time taken.

• On rearranging,

        $t = \frac{d}{s}$

• On replacing the terms with the values given in the question, the obtained equation is,

        $6 hr = \frac{30km}{x + 12km/hr} + \frac{30km}{x - 12km/hr}$

• In the first case, the speed of wind is added to the speed of the electric bike because it travels in direction of the speed of the wind.
• Since while returning the direction becomes opposite, the speed of wind is subtracted.

• On rearranging and solving further, a quadratic equation is formed.

        $x^{2} -10x -144 = 0$

        $x = 18$

Therefore, the speed of the electric bike is 18km/hr.