12. Jane was playing basketball. After a series of 20 shots, Jane had a success rate of $55 \%$. Five shots later, her success rate had increased to $56 \%$. On how many of the last five shots did Jane score?
A 1
B 2
C 3
D 4
E 5
12. C Since Jane had a success rate of $55 \%$ after her first 20 shots, the number of times she had scored out of 20 was $0.55 \times 20=11$. Similarly, since her success rate had increased to $56 \%$ after 5 more shots, the number of times she had scored out of 25 was $0.56 \times 25=14$. Hence the number of shots she scored out of the last five was $14-11=3$.