1. It is known that the speed of passenger cars is 60 kilometers per hour and that of trucks is 50 kilometers per hour. Now, two cars enter together and leave from A and B, which are 200 kilometers apart. How many kilometers are the two cars apart in two hours?

Teacher Zhang wants to buy a computer. In order to spend as little money as possible, he visited three shopping malls, A, B and C. The computer he wanted to buy was available in all three shopping malls, and the price was 9980 yuan. All three shopping malls have discounts. Specifically:

A shopping mall: 10% off the whole audience (10% off the marked price of the purchased goods)

Mall B: Buy 1 1,000 yuan and get 1 1,000 yuan.

Mall C: 10% discount for shopping over 1000 yuan, and 8.8% discount for shopping over 10000 yuan.

Teacher Zhang brought 10000 yuan. If necessary, besides computers, he plans to buy some computer software and use up all his money. Which shopping mall should teacher Zhang go to to buy a computer? Please explain why?

That's all I know. I hope I can help you.