An Internet bar, Members normally surf the Internet for 3 yuan an hour, and now they are engaged in activities, 50 for charging, 100 for charging, 100 for charging, 200 for charging, 300 for charging It used to be 50 for 20, 100 for 50 Which rate is cost-effective and how to calculate it? My brother and sister help me with the calculation problem given by the teacher

An Internet bar, Members normally surf the Internet for 3 yuan an hour, and now they are engaged in activities, 50 for charging, 100 for charging, 100 for charging, 200 for charging, 300 for charging It used to be 50 for 20, 100 for 50 Which rate is cost-effective and how to calculate it? My brother and sister help me with the calculation problem given by the teacher

Rate:
50:50 / (100 / 3) = 1.5 yuan / hour
100:100 / (200 / 3) = 1.5 yuan / hour
Free 200 free 300: 200 / (500 / 3) = 1.2 yuan / hour
50 free 20:50 / (70 / 3) = 2.14 yuan / hour
50:100 / (150 / 3) = 2 yuan / hour
Which rate is higher, which is lower, you can see for yourself