Manufacturer 6981

The hotelier wanted to equip the dining room with new chairs. He chose the type of chair in the catalog. Only when placing an order did he learn from the manufacturer that they offered every fourth chair at half price as part of the discount offer and that he could save seven and a half chairs compared to the plan. The hotelier calculated that he could get nine more chairs than he had intended for the originally planned amount. How many chairs did the hotelier want to buy?

Correct answer:

n =  63

Step-by-step explanation:

$$\begin{gathered} 7.5=0.5\cdot n/4 \\ n:60,61,62,63 \\ np=(9+n)\cdot (p-p/4/2) \\ (9+n)\cdot 7=8\cdot n \\ n=63 \\ n=\frac{63}{1}=63 \\ n=63 \\ m=9+n=9+63=72 \\ t=m/4=72/4=18 \end{gathered}$$

Try another example