Non-bank loan

Mrs. Smetanová took a non-bank loan. The monthly fee is calculated using a basic fee. The basic fee of 60 Kč is each month multiplied by the number of months for which Mrs. Smetanová knows the money borrowed (1st month = 1 × 60 Kč, 2nd month = 2 × 60 Kč, ...). Every half-year a fifth of the fees paid for the given period is deducted. How many crowns will Mrs. Smetanová pay in total in fees, if in January she borrows 12 000 Kč and repays them in August?

Final Answer:

x =  1980 Kc

Step-by-step explanation:

$$\begin{gathered} a=60+2\cdot 60+3\cdot 60+4\cdot 60+5\cdot 60+6\cdot 60=1260\text{Kc} \\ b=7\cdot 60+8\cdot 60=900\text{Kc} \\ x=a-b/5+b=1260-900/5+900=1980\text{Kc} \end{gathered}$$

Try another example