To find the percent, you will double everything because you only have 50 as the base and doubled its 100. 41 times 2 it’s equal to 82 so 82% of the bicyclists finished in less than 38 minutes. As a fraction it would be 41 over 50.
Well since the triangle is split into 2 triangles and they both are the same size so BD on the bottom is 15 which means naturally BC must be 30. Five I'm not sure about