A hexagon has six sides. Each of the six sides of the black tile must touch a side of a white tile, so there are six white tiles surrounding black tiles

The train headed for Wichita traveled 55 miles per hour 3 hours = 165 total miles. The train headed for Des Moines traveled 70 miles per hour 3 hours = 210 total miles. Adding the distances together gives you the number of miles apart the two trains were after three hours: 210 + 165 = 375. Another option: You can add the two rates of speed (55 + 70) and multiply the sum by 3 hours (125 3 hours = 375).