Visitors to show were charged Rs.15 each on the first day. Rs.7.50 on the second day, Rs.2.50 on the third day and total attendance on the three days were in ratio 2:5:13 respectively. The average charge per person for the whole show is ____ ?
A. Rs.7.50
B. Rs.5.00
C. Rs.3
D. Rs.4.50