Ashok and Harish are very close friends. They decided to go on a long drive with their families in separate cars. Ashok's car travels at a speed of x km/h, while Harish was driving the car at a speed of 5 km/h faster than Ashok's car. Ashok took 4 hours more than Harish to complete the journey of 400 km. Based on the above information, answer the following questions : (i) Find the distance covered by Harish's car in two hours (in terms of x). (1) (ii) Make a quadratic equation describing the speed of Ashok's car. (1) (iii) (a) Find the speed of Ashok's car (in km/h). (2) OR (b) Find the speed of Harish's car (in km/h). (2)

Answer: (i) The distance covered by Harish's car in two hours is 2(x+5)2(x+5) km. (ii) The quadratic equation describing the speed of Ashok's car is x2+5x−500=0x^2 + 5x - 500 = 0. (iii) (a) The speed of Ashok's car is 20 km/h. (iii) (b) The speed of Harish's car is 25 km/h.

Step-by-step solution

Step 1: Define speeds and calculate distance for Harish

First, we define the speeds of Ashok's and Harish's cars based on the given information. Ashok's speed is xx km/h, and Harish's speed is 5 km/h faster, so it is (x+5)(x+5) km/h. To find the distance covered by Harish's car in two hours, we multiply his speed by the time.

Step 2: Formulate time taken for each car

The total distance for the journey is 400 km. We use the formula Time = Distance / Speed to express the time taken by Ashok (TAT_A) and Harish (THT_H) in terms of xx.

Step 3: Set up the quadratic equation

We are given that Ashok took 4 hours more than Harish. So, we set up the equation TA=TH+4T_A = T_H + 4. Substituting the expressions for TAT_A and THT_H, we then simplify the equation by finding a common denominator and rearranging terms to form a quadratic equation.

Step 4: Solve the quadratic equation for x

We solve the quadratic equation x2+5x−500=0x^2 + 5x - 500 = 0 using the quadratic formula. The formula provides two possible values for xx. Since speed cannot be negative, we discard the negative solution.

Step 5: Calculate speeds

From the quadratic equation, we found x=20x=20. This is Ashok's speed. Harish's speed is x+5x+5, which is 20+5=2520+5=25 km/h.

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