Question

the distance between two places A and B on road is 70 km.A car starts from A and the other from B.if they travel in the same direction they will meet after 7 hours if they travel towards each other they will meet after 1 hour then find their speeds​

Answer 1

Answer:

distance between A and B =70km

speed of A=x

speed of B=y

In same direction=7(x-y)=70

=x-y=10

In opposite direction=1(x+y)=70

=x+y=70

x-y=10

x+y=70

2x=80

x=40

x+y=70

40+y=70

y=70-40

y=30

speed of A=x=40km/hr

speed of B=y=30km/hr

Answer 2

The speed of car A is $x = 40 \frac{km}{hr}$

The speed of car B is $y = 30\frac{km}{hr}$

Step-by-step explanation:

Distance = 70 km

Let speed of car A = x

Speed of car B = y

Relative speed when the car runs in the same direction = x - y

Relative speed when the car runs in the opposite direction = x + y

Given that if they travel in the same direction they will meet after 7 hours.

⇒ Distance = (x - y) × 7

⇒ 70 =  (x - y) × 7

⇒ x - y = 10 -------- (1)

And  if they travel in the opposite direction they will meet after 1 hours.

⇒ 70 =  (x - y) × 1

⇒ x + y = 70 -------- (2)

Now add equation (1) & (2)

⇒ 2 x = 80

⇒ $x = 40 \frac{km}{hr}$

Put the value of x in equation (2)

y = 70 - 40

⇒ $y = 30\frac{km}{hr}$

Therefore, the speed of car A is $x = 40 \frac{km}{hr}$

The speed of car B is $y = 30\frac{km}{hr}$