Two cars A and B are seprated by a distance of 0.5 km and moving in the same direction with same speed. A car C moving with 10 km/h in opposite direction meets these cars at an interval of 1 minute. The speed of A and B is
The relative speed of A,B and C is x+10
It takes C 1 minute at (x+10)km/hr to cover the 0.5km distance. So,
(x+10)(1/60) = 1/2
x = 30 km/hr
Or, let the rear car be at point 0, and the front car at 0.5. The rear car is moving in the + direction, and C is moving in the - direction. Then we want their positions to be the same at t=1/60 hr:
x(1/60) = 1/2 - 1/60 (10)
x = 30