在为期 5 天的促销活动开始时，A 和 B 两家商店各有 100 台相同的笔记本电脑。下面的图表显示了每家商店在每天结束时未售出的笔记本电脑总数。

1. Calculate the number of laptops sold each day for Shop A and Shop B by finding the difference in unsold laptops from the previous day.

For Shop A, the number of laptops sold each day is:

• Day 1: $100 - 80 = 20$
• Day 2: $80 - 60 = 20$
• Day 3: $60 - 30 = 30$
• Day 4: $30 - 10 = 20$
• Day 5: $10 - 0 = 10$

For Shop B, the number of laptops sold each day is:

• Day 1: $100 - 90 = 10$
• Day 2: $90 - 60 = 30$
• Day 3: $60 - 40 = 20$
• Day 4: $40 - 10 = 30$
• Day 5: $10 - 0 = 10$

2. Compare the daily sales to identify the days when Shop A sold fewer laptops than Shop B.

Comparing the sales (Shop A vs Shop B):

• Day 1: $20 > 10$
• Day 2: $20 < 30$ (Shop A sold fewer)
• Day 3: $30 > 20$
• Day 4: $20 < 30$ (Shop A sold fewer)
• Day 5: $10 = 10$

Shop A sold fewer laptops on Day 2 and Day 4.

1. Determine the discounted price for each $300 block of the original price

For every $\char36{}300$ of the original price, the discount is $\char36{}50$.
Discounted price per block = $\char36{}300 - \char36{}50 = \char36{}250$.

2. Find the number of full $250 blocks in the total amount paid

Total amount paid = $\char36{}4600$.
Number of full blocks = $4600 \div 250 = 18$ with a remainder of $\char36{}100$.

3. Calculate the original price without the discount

Original price of the 18 blocks = $18 \times \char36{}300 = \char36{}5400$.
The remaining $\char36{}100$ paid did not qualify for a discount, so its original price is $\char36{}100$.
Total original price = $\char36{}5400 + \char36{}100 = \char36{}5500$.