Question

point A and B are 90 km apart from each other on a highway A car starts from A and another from B at the same time if they go in same Direction they meet in 9 hours if they go in opposite direction they meet in 9.7 hours find the speed

Answer 1

let 1st car be x
let 2nd car be y
   moving from point a and b respectively.
speed of car x= x km/h
speed of cary= y km/h

case1: when they move in the same directions.
 they meet in 9hrs
distance by x= 9x
distance by y= 9y
=> 9x-9y=90
x-y=10             (1)
case 2: when they move in opposite direction
they meet after 9.7 hrs
distance by x= 9.7x
distance by y= 9.7y

=> 9.7x+9.7y=90
x+y=9.27..              (2)


on equating and solving the two equations, you'll get your desired answer.

 

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