Fig. 3.26.
Let the speeds of two cars be x km./hr. and y km/hr.
Then, according to the given problem,
5x - 5y = 100
⇒ x - y = 20 ...(i)
and x + y = 100 ...(ii)
By adding, we get 2x = 120
⇒ x = 60
By subtracting, we get 2y = 80
⇒ y = 40
Hence, the required speeds of the two cars are: 60 km/hr. and 40 km/hr.
Solve the following system of equations by elimination method
6(ax + by) = 3a + 2b
6(bx - ay) =3b - 2a.
A motor boat whose speed is 24 km/h in still water takes 1 hour more to go 32km upstream than to return downstream to the same spot. Find the speed of the stream.
If the points A(k + 1, 2k), B(3k, 2k + 3) and C(5k – 1, 5k) are collinear, then find the value of k.