✔ 最佳答案
Sub-problems are the problems that are easier to solve and build up your whole solutions if you group their solution togather.
Give you an examples :
Suspose you need to design a house, then you will encounter :
1) how the house look like ? Chinese-style or Western-style ?
2) what materials should I use to build ? Wood or Stone ?
3) how many floors the house should have ? one or two ?
....
....
These are the sub-problems of the original problem "Design a house". After you got the answers for these problems, you can use these solution to systemically build up your solution.
P.S. IT tools are anythings in a computer system. The hardwares likes keyboard, mouse, barcode scanner, LCD screen and softwares like Windows, Database System, are counted in IT tools.
