The regular price for a bicycle is \$320. The bicycle is on sale for 20\% off. The regular price for a helmet is \$80. The helmet is on sale for 10\% off. If Sandra bought both items on sale, what is her percentage savings on the total purchase?
Answer Choices
A. 18\%
B. 12\%
C. 15\%
D. 19\%
E. 22.5\%