Question

Places A and B are 100km apart from each other on a highway. A car starts from A and another from B at the same time. If they move in the same direction, they meet in 10 hours and if they move in opposite directions, they meet in 1 hour and 40 minutes. Find the speeds of the cars.

Answer 1

Speed of the first car = x = 35km/hr

Speed of the second car = 25km /hr

Step-by-step explanation:

The calculation of speeds of the cars is given below:-

Assume that the speed of the 1st car which is opening from A = x km/hr

and assume the Speed of the 2nd car which is starting from B

= y km/hr

As we know that

Time = Distance ÷ Speed

So, the distance lies between two places i.e. A and B are

80km d = 80 km

1. now when the car moves in the similar direction

So, the corresponding speed of them = (x + y)km/hr

Time = 8hr

d = 80km

`8 = (80)/((x + y))\\\\x + y = (80)/(8)\\\\x + y = 10 ..... (i)`

2. when two cars moving in the inverse direction,

So, the corressponding speed = (x - y) km / hr

Time = 1 hr 20 minutes

That means

= (1 + 20 ÷ 60) hr

= (80 ÷ 60)

= 4/3 hr

d = 80km

Now

4 ÷ 3 = 80 ÷ (x -y)

x -y = (80 × 3) ÷ 4

x - y = 60 ..... (ii)

Now, we will sum equation 1 and equation 2 we will get

2x = 70

x = 35

now, Put x = 35 in (i) we will get

y = 25

Speed of the first car = x = 35km/hr

Speed of the second car = 25km /hr