Mary is 20 \% older than Sally, and Sally is 40 \% younger than Danielle. The sum of their ages is 23.2 years. How old will Mary be on her next birthday?
Answer Choices
A. 7
B. 8
C. 9
D. 10
E. 11
Mary is 20 \% older than Sally, and Sally is 40 \% younger than Danielle. The sum of their ages is 23.2 years. How old will Mary be on her next birthday?
Answer Choices
A. 7
B. 8
C. 9
D. 10
E. 11