Question

2 stations A and B are 90 km apart on a high way. two cars start at the same time from A and B. if they drive in opposite directions they meet in 1, 2/7 hours if they continue in same direction they meet in 9 hrs. find the speed of both cars.

Answer 1

Answer:

Speed of cars which start from A and B are 40 and 30 respectively.

Step-by-step explanation:

Given:

Distance between two stations = 90 km

if they drive in opposite directions they meet in 1 2/7 hours.

if they continue in same direction they meet in 9 hrs.

Formula Used

Relative speed in Opposite direction = Sum of Speeds

Relative speed in same direction = Difference of speeds

Distance = Speed * time

Solution

Let X and Y be the speed of two cars.

First case:

Relative speed in Opposite direction = Sum of Speeds

Speed = x + y

Time = 9/7 hours

$90 = (x + y) \times \frac{9}{7} \\ x + y =70 \: .....(1)$

Second Case:

Relative speed in same direction = Difference of speeds

Speed = x - y

Time = 9 hours

$90 = (x - y) \times 9 \\ \: x - y = 10 \: .....(2)$

Solve equation (1) and (2)

$x = 40 \\ y = 30$

Answer

Speed of cars which start from A and B are 40 and 30 respectively.