There were 49 trees in an orchard, arranged in a 7x7 grid. The gardener decided that the orchard was too crowded, so he wanted to clear the garden of excess trees to make flowerbeds. He called in a workman and ordered: "Leave only five rows of trees, with four trees in each row. Cut down the rest... (more) A marching band is parading down Main Street at a constant speed. The bass drum player has a dog that runs to the front row and then back to its owner, going back and forth, also at a constant speed. The distance between the back row and front row of the marching band is 50 feet. In the time the ... (more) There are 25 horses and 5 race tracks. How many minimum races you have to run among them to ensure you select the fastest 5 horses?