please show steps $($don$$t use excel$)$

A firm sells its products on terms of net $30$ at $$115$ for each unit. The present value of the production cost is $$83$ per unit. The monthly interest rate is $1\%,$ and there are $30$ days every month. It is estimated that only $86\%$ of all orders will be eventually collectable. Orders come in $100$ units. What is the expected profit$/$loss per order?

a$.$

$$3,086$

b$.$

$$1,590$

c$.$

$$3,703$

d$.$

$$1,243$

e$.$

$$1,492$

the answer is not b