Exchange Rate Pencils Erasers

Pupils exchanged pencils, erasers, and pens so that there were two pens for 15 pencils and three pencils for two erasers. How many erasers were there for one pen?

Final Answer:

p =  5 g

Step-by-step explanation:

$$\begin{gathered} 15t=2p \\ 2g=3t \\ p=\frac{15}{2}t \\ p=\frac{15}{2}\cdot \frac{2}{3}g \\ p=\frac{15}{2}\cdot \frac{2}{3}=\frac{15\cdot 2}{2\cdot 3}=\frac{30}{6}=5\text{g} \end{gathered}$$

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