I'm thinking you'll have to translate that to English.

What does this mean:

1) "without input"

2) "each service"

3) "one of them is given as input"

4) "other benefits"

benefits = service = installment = payment or deposit?

input = down payment?

Is that exactly how the question is worded? Is this the original language? Perhaps a quick example or two would clear it up. Show how to calculate one payment at the end of the year with and without inputs. Include the language that would describe the situation.

I might rephrase the question in this manner:

A person wants to buy a set of upholstery valued at $3500,00. To finance the purchase in 4 equal MONTHLY installments without a downpayment, each INSTALLMENT will be $930,36. If, however, one of the INSTALLMENTS is given as a DOWNPAYMENT, the four MONTHLY INSTALLMENTS are reduced to $ 907,67.

I might rephrase this way, as well.

A person wants to buy a set of upholstery valued at $3500,00. To finance the purchase in 4 equal MONTHLY installments without a downpayment, each INSTALLMENT will be $930,36. Just in case you can't calculate an annuity immediate, here is the same problem as an annuity due. If one of the INSTALLMENTS is given as A DOWNPAYMENT, the four MONTHLY INSTALLMENTS are reduced to $907,67.

I get "e" working as Immediate or as Due. I am a little puzzled why both were give as if all the information were needed. Either one will do.

Really, the problem statement does NOT define the frequency of payments. There is a HINT as the question asks for "monthly rate", but this is not good enough. Please ask the problem's author to step it up a bit. This is a poorly prepared problem statement even without the translation difficulties.