34. The average speed of a car is 20km/hr more than the average speed

1.	34. The average speed of a car is 20km/hr more than the average speed of a Bus. Ifthe car takes 4 hours less than the bus to cover a distance of 300 km. Find theaverage speed of the car and the bus.
Answer» Let b be the speed of the bus. Then the car is b+20. So: 300/b - 4=300/b+20 300(b+20) -4b²-80b=300b 4b²+80b-6000=0 b²+20b-1500=0 (b+50)(b-30)=0 b=30 The bus goes 30 kph; the car goes 50 kph

34. The average speed of a car is 20km/hr more than the average speed of a Bus. Ifthe car takes 4 hours less than the bus to cover a distance of 300 km. Find theaverage speed of the car and the bus.

Answer»

Let b be the speed of the bus. Then the car is b+20. So:

300/b - 4=300/b+20

300(b+20) -4b²-80b=300b

4b²+80b-6000=0

b²+20b-1500=0

(b+50)(b-30)=0

b=30

The bus goes 30 kph; the car goes 50 kph