In theory you can use as many as you want. In practice you would use very few. Usually all the numbers would be the same font. You might bold some of the totals to make them stand out, or use other formatting, such as a border around the cells with totals, or borders between the regular data and totals.
For headings and other text you might use a few fonts, but there should be some consistency. So you could have one font for major headings and another font for others of the same level of importance.
The most important thing in any spreadsheet is that all the figures are right. Having a spreadsheet with fancy colours and fancy fonts is not much good if the figures are wrong or formulas don't work properly. Fonts and other formatting are just cosmetic and variety is generally kept to a minimum. So normally you won't have many different fonts in a spreadsheet.
TRUE type font, Script fonts, Post script font
There are many different types of fonts in the font family. Examples of different types of fonts in the font family includes Times New Roman, Helvetica, and Arial.
Four
You may be referring to functions, of which Excel has many types of.
No more than two
Excel includes 11 chart types. Source: Office 2007 Concepts and Techniques. Shelly Cashman Series
There are 3 types of cell addressing or cell referencing mechanisms in Excel. They are relative, mixed and absolute.
You cannot. The whole point of Excel Viewer is to be able to read-only view an excel spreadsheet, even though you do not have Excel. You will have to purchase or find a copy of Excel if you wish to edit the spreadsheet.
There would not be a set limit. Generally you would use common sense and have some consistencies in how you use your fonts, like having the same font for all numbers, but maybe having some variations in fonts for different kinds of headings, like a different font for a main heading than for ordinary headings. Sometimes it is better to use the same font and having main headings bolded or a larger font size than the other headings. Whatever approach you use, the same types of headings should be consistent in the font they use. Like using too many colours, too many fonts can look bad. The most important thing in a worksheet is to have all the calculations correct, not to have it looking stylish.
Ribbon command include almost everything that you might want to do with Excel, such as setting the font and controlling the appearance of the font. Ribbon commands also let you create charts and graphs, import and export data, format cells, and more.
This is not a question. Please ask this question again using words that indicate what you want to know. Excel can use many different types of lists.
You probably would not use Excel for a presentation. For PowerPoint slides, use font sizes of 28 to 32 points. Anything smaller may be too small to see from the back of the room.