Question

Two places a & b are 120km apart from each other on highway. A car starts from a and another from b at the same time. If they move in the same direction. They meet in 6 hrs and if they move in opposite directions, they meet in 1 hour and 12 minutes. Find the speed of cars.

Answer 1

Answer:

Let speed of car starting at A = x km/hr

and speed of car starting at B = y km/hr

∴ x + y = 120 ..........(let it be equation 1)

6x - 6y = 120 .........(let it be equation 2)

Now: from equations 1 and 2 we can find that :-

.:  x = 70 km/hr .

y = 50 km/hr.

I think it helps u buddy........ ;-)

Answer 2

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