Use different formula to calculation based on conditions

Hi.
It's the look of my Excel file:

Item 1----Amount
Category---Details: ...
Item 2----Amount
Category---Details: ...
Item 3----Amount
Category---Details: ...
Item 4----Amount
Category---Details: ...

As you see:
- A1 is the item's name; A2 is the price/amount/cost/value of the item
- B1 is the category the item belongs to; B2 is the description of the item.

Now I would like to do some math which are the following:
1) If the category type is income, add all of them
2) If the category type is one-off expense, add all of them & put a minus sign
in front of the value
3) If the category type is daily expense, add all of them & times 30, & put a
minus sign in front of the value
4) If the category type is Asset A, put each amount of the item in this
calculation: (Amount-1000)*3/5
and so on

How can I achieve this?
Thanks a lot.

--
Additional information:
- I'm using Office XP
- I'm using Windows XP

"0-0 Wai Wai ^-^" wrote:
> It's the look of my Excel file:
> Item 1----Amount
> Category---Details: ...
> Item 2----Amount
> Category---Details: ...
> [....]
> - A1 is the item's name; A2 is the price/amount/cost/value
> of the item
> - B1 is the category the item belongs to; B2 is the description
> of the item.

What a screwy way to organize information in spreadsheet.
Someone might have a solution for your arrangement. But
it might be better to reorganize the spreadsheet in a more
reasonable. Something like the following:

Column A: Item
Column B: Amount
Column C: Category
Column D: Description

Row 1 for Item 1; row 2 for item 2; etc.

That is probably not the answer you want to hear. But
sometimes it is an important learn when you are using a
tool fundamentally wrong or poorly. It will help you in the
future, if not now.

Then there are simple solutions to your problems, namely
(assuming you have 10 items) ....

> 1) If the category type is income, add all of them

=SUMIF(C1:C10,"Income",B1:B10)

> 2) If the category type is one-off expense, add all of them
& put a minus sign in front of the value

=-SUMIF(C1:C10,"One-off Expense",B1:B10)

> 3) If the category type is daily expense, add all of them &
times 30, & put a minus sign in front of the value

=-30*SUMIF(C1:C10,"Daily Expense",B1:B10)

> 4) If the category type is Asset A, put each amount of the
item in this calculation: (Amount-1000)*3/5

=IF(C1="Asset A",(B1-1000)*3/5,"")

I suspect you want something different for #4, but your
description is not clear enough to know for sure. I suspect
you meant to say that you want the sum of
(AssetA Amount - 1000)*3/5. That would be:

=(SUMIF(C1:C10,"Asset A",B1:B10)
-1000*COUNTIF(C1:C10,"Asset A",B1:B10))*3/5

Hope that helps in some small way. It is not directly applicable
to the organization of your data.

Errata ....

I wrote:
> =(SUMIF(C1:C10,"Asset A",B1:B10)
> -1000*COUNTIF(C1:C10,"Asset A",B1:B10))*3/5

Of course, that should be COUNTIF(C1:C10,"Asset A").