Need help with correct function or input for this problem/scenario

[Dan R]

I have a situation where I am creating a borrowing base for a company. (I am
going to shorten numbers to make it easier.)
There is a $300 loan.
Type A loan can borrow up to $300.
Type B loan can borrow up to $150.
Type C loan can borrow up to $50.

I need a formula to input in excel that will give me a borrowing base for
type B and C loans. For example, to borrow in type B loans, I have to check
1-what's outstanding on the entire loan.
2-what's outstanding on type B loans.
3-Take those two numbers and figure out what can be advanced under the
answer to those questions. (I.E. $200 outstanding, $100 - type A, $100 type
B, how much is remaining in type B to borrow?) I need a function that will
easily do that for me. What function would I use? IF, OR, or something else?
I have a column with function for total loan availability, and total
borrowed under each loan type. If someone could help me with the logistics
for this scenario, I would greatly appreciate it!!
Thanks in advance,
Dan

 

[arun_bhilai]

dear Dan R,
can u please give a specific example from start to end and all that u
exactly want to obtain and the inputs that u can give for the problem.
sorry but i couldn't get what exactly u want to say.