Speed is the ditance traveled by a certain object given a certain time span. To solve this problem we need to divide the distance by the time given. Before that, the problem asked us to get the speed in terms of miles per minute and we are given a distance of 3 kilometer. We have to convert this to miles. 3km(0.6miles/km) = 1.8 miles. The speed is then 1.8/20 = 0.09mi/min.