Sneaker discount

Igor paid only €12 for trainers instead of €15. By what percentage did he pay less? By what percentage did the price of the trainers decrease?

Final Answer:

x =  20 %
y =  80 %

Step-by-step explanation:

$$\begin{gathered} a=15\text{eur} \\ b=12\text{eur} \\ x=\frac{a-b}{a}\cdot 100=\frac{15-12}{15}\cdot 100=20\% \end{gathered}$$

$y=\frac{b}{a}\cdot 100=\frac{12}{15}\cdot 100=\frac{12\cdot 100}{15}=\frac{1200}{15}=80\%$

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