Question

A car and a motorcycle leave the city at the same time and drive to a lake that is 120 km away. The speed of the motorcycle is 20 km per hour greater than the speed of the car, so the motorcycle arrives at the lake 1 hour before the car. Find the speed of the car and the speed of the motorcycle. Plz answer fast!!

Answer 1

Speed of the car is 40 km/h

Speed of the motorcycle is 60 km/h

Answer 2

• 40 km/h and 60 km/h

Explanation:

Let the speed of the car is x, then the speed of motorcycle is x + 20

The distance = 120 km

Time:

• 120/x = 120/(x + 20) + 1
• 120(x + 20) = 120x + x(x +20)
• 120x + 2400 = 120x + x² + 20x
• x² + 20x = 2400
• x² + 2*10x + 10² = 2500
• (x + 10)² = 50²
• x + 10 = 50
• x = 40

Speed of the car is 40 km/h

Speed of the motorcycle is 60 km/h