儿童观看魔术表演的门票价格在一周内是固定的。周四，有 80 名男孩 and 60 名女孩观看了表演。周五，男孩人数增加了 30%，女孩人数减少了 15%。这两天售出门票的总收入为 $9440。

1. Calculate the number of boys and girls who attended the show on Friday.

Number of boys on Friday = $80 \times (1 + 0.30) = 80 \times 1.3 = 104$
Number of girls on Friday = $60 \times (1 - 0.15) = 60 \times 0.85 = 51$

2. Find the total number of tickets sold over the two days.

Tickets sold on Thursday = $80 + 60 = 140$
Tickets sold on Friday = $104 + 51 = 155$
Total tickets sold = $140 + 155 = 295$

3. Calculate the price of each admission ticket.

Price per ticket = $\char36{}9440 \div 295 = \char36{}32$

1. Find the total number of tickets sold on Thursday.

Total tickets on Thursday = $80 + 60 = 140$

2. Find the number of boys and girls who attended on Friday.

Number of boys on Friday = $80 \times (1 + 0.30) = 80 \times 1.3 = 104$
Number of girls on Friday = $60 \times (1 - 0.15) = 60 \times 0.85 = 51$

3. Calculate the percentage increase in the total number of tickets sold.

Total tickets on Friday = $104 + 51 = 155$
Increase in tickets = $155 - 140 = 15$
Percentage increase = $\frac{15}{140} \times 100\% = \frac{3}{28} \times 100\% = \frac{75}{7}\% = 10\frac{5}{7}\%$