and speed of stream=y km/hourx+y=8x-y=4x=6 km/hour.
A clock only with only dots marking 3, 6, 9 and 12 positions has been kept upside down in front of mirror. A person reads the time in the reflection of the clock as 4.50. What is the actual time?
A train moving at speed of 90 km/hr crosses a pole in 7 seconds. Find the length of the train.