Kim starts to walk 3 mi to school at

7:30 A.M. with a temperature of 0°F. Her brother Bryan starts at 7:50 A.M. on his bicycle, traveling 10 mph faster
than Kim. If they get to school at the same time, then how fast is each one traveling?

I have tried to answer this word problem by using the formula d=rt, and the try and figure out what is the value of r. I got a complex fraction of -30t+19/3t-1. I want to know if I am right or wrong. If I am wrong, could you walk me through the steps to sovling this word problem. Thank so much for your time, and help.