Places A and B are 80 km a part from each other on a highway. One car starts from and another from B at the same time.If they move in the same direction,they meet in 8 hours and if they move in opposite directions they meet in 1 hour and 20 minutes. Find the speeds of the car.
Answers
Answered by
3
see diagrams.
When A and B travel in the same direction, distance traveled by B is the distance traveled by A + 80km.
VA * 8 hours + 80 km = VB * 8 hours
VB - VA = 80 km / 8 hours = 10 kmph equation 1
When A and B travel towards each other, the distance traveled by both is 80 km.
VA * 80 minutes + VB * 80 minutes = 80 km
VA+ VB = 80 km / (80/60) hours = 60 km ph equation 2
Add both equations to get,
2 VB = 70 kmph VB = 35 kmph
VA = VB - 10 = 25 kmph
When A and B travel in the same direction, distance traveled by B is the distance traveled by A + 80km.
VA * 8 hours + 80 km = VB * 8 hours
VB - VA = 80 km / 8 hours = 10 kmph equation 1
When A and B travel towards each other, the distance traveled by both is 80 km.
VA * 80 minutes + VB * 80 minutes = 80 km
VA+ VB = 80 km / (80/60) hours = 60 km ph equation 2
Add both equations to get,
2 VB = 70 kmph VB = 35 kmph
VA = VB - 10 = 25 kmph
Attachments:
Answered by
0
Let the speed of car start from A is X km/h And the speed of other car start from B is Y km/h
Similar questions