A boat covers 143 km upstream in 13 hours and the same distance downstream in 11 hours. What is the speed (in km / hr ) of the boat in still (without stream) water?
10 km/hr
12 km/hr
14 km/hr
8 km/hr
The speed of three cars is in the ratio of 2 : 3 : 4 . The ratio of the times taken by these cars to travel the same distance is -
A man swimming in a stream which flows 112km/hr finds that in a given time he can swim twice as far with the stream as he can against it. At what rate does he swim?
A student walks from his house at a speed of 2 12 K per hour and reaches his school 6 minutes late. The next day he increases his speed by 1 km per hour and reaches 6 minutes before school time. How far is the school from his house?
In a class 75% passed in English, 60% in Mathematics and 25% failed in both the subjects. What is the percentage who passed in both subjects?