Answer :
Part A. How many total yards did Ed run in the first 3 football games.
total yards Ed = 157 + 309 + 172 = 638
Part B. How many more total running yards did Rico have than Ed after the first 3 games of the season?
total yards Rico = 3*total yards Ed = 3*638 = 1914
so Rico has more yards than Ed, 1914 - 638 = 1276, that is, Rico has 1276 more yards than Ed after the 3 first games
total yards Ed = 157 + 309 + 172 = 638
Part B. How many more total running yards did Rico have than Ed after the first 3 games of the season?
total yards Rico = 3*total yards Ed = 3*638 = 1914
so Rico has more yards than Ed, 1914 - 638 = 1276, that is, Rico has 1276 more yards than Ed after the 3 first games