Question

一件商品打八折出售现价比原价便宜了百分之几，售价400元原价是多少元

列式

Answer 1

400/0.8=500（元）

Answer 2

便宜了20%（1-80%）=20%，原价是500,400/0.8=500

Answer 3

400/0.8=500（元）

Answer 4

1-0.8=0.2=20%
400除以80%=500（元）

Answer 5

The Internet
The Intemet was first established in 1960s. At that time, the computer was both large and expensive and the networks were unable to work well. If one of the computers broke down, the whole networks would be unable to work.
At first, the Intemet was just used by the government. By 1970s, it had been used in universities, banks and hospitals. At the beginning of 1990s, computers became both cheaper and easier to operate. Now it is very convenient to log on the Internet.
It is said that each day tens of millions of people log on the Internet.Sending e-mails is becoming more and more popular.
The Internet has become the most important part of people's life.