At what profit percent must an article be sold so that by selling at half that price, there will be a loss of 30%?
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 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?