In an h meter race, Sunny is exactly d meters ahead of Windy when Sunny finished the race. The next time they race, Sunny sportingly starts d meters behind Windy, who is at the starting line. Both runners run at the same constant speed as they did in the first race. In terms of h and d, how many meters ahead is Sunny when Sunny finishes the race?
Sumant's 1 page of Math 