places A and B are 100 km apart on a highway. one car starts from A and another from B at the same time . if the cars travel in the same direction at different speeds , they meet in 5 hours . if they travel towards each other , they meet in 1 hour .what are the speeds of the two cars?
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Speeds of cars at places A and B are 60 km/h and 40 km/ h respectively
places A and B are 100 km apart on a highway. one car starts from A and another from B at the same time . if the cars travel in the same direction at different speeds , they meet in 5 hours . if they travel towards each other , they meet in 1 hour .what are the speeds of the two cars?
Let the cars from A and B start at speeds x km/h and y km/h respectively
Then,
5x - 5y = 100
==> x - y = 20 ..........( 1 )
and x + y = 100..........( 2 )
Adding ( 1 ) & ( 2 ) , we get
2x = 120
=> x = 60
•°• from ( 1 ), y = 60 - 20
•°• y = 40
•°• Speeds of cars at places A and B are 60 km/h and 40 km/ h respectively
Anonymous:
Nice explained!!
Answered by
17
Let the speed of the first car which starts from A = x km /hr
Speed of the second car which starts from B = y km / hr
Time = distance / speed
Distance between two places A andB are 80km d = 80 km
i ) if the cars move in same direction
Relative speed of them = ( x + y )km/hr
Time = 8hr
d = 80km
8 = 80 / ( x + y )
x + y = 80 / 8
x + y = 10 ------( 1 )
ii ) if two cars moving opposite direction, Relative speed = ( x - y ) km / hr
Time = 1 hr 20 minutes
= ( 1 + 20 / 60 ) hr
= ( 80/60)
= 4/3 hr
d = 80km
4/3 = 80 / ( x -y )
x -y = ( 80 × 3 ) / 4
x - y = 60-----( 2 )
Add ( 1 ) and ( 2 ) , we get
2x = 70
x = 35
Put x = 35 in ( 1 ) we get ,
y = 25
so,
Speed of the first car = x = 35km/hr
Speed of the second car = 25km /hr
hope it helps you mark as brainliest please
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