Math problem questions???

At 10a.m. Danny has travelled 36km .That means Danny is 36 km ahead of his brother. His brother will travel 54-18=36km faster than Danny every hour . Therefore it takes him 1 hour to catch up with Dannyi.e. 11a.m..Since Danny left home at 8a.m., Danny has travelled 3 hours when his brother overtook him.The distance that Danny travel is 3x18=54km