AMC 12A 2010 Problem 5

Halfway through a 100-shot archery tournament, Chelsea leads by 50 points. For each shot a bullseye scores 10 points, with other possible scores being 8 , 4,2 , and 0 points. Chelsea always scores at least 4 points on each shot. If Chelsea’s next n shots are bulleyes she will be guaranteed victory. What is the minimum value for n ?

Answer Choices
A. 38
B. 40
C. 42
D. 44
E. 46