solution: We have $\frac{7}{30}@\frac{10}{21}=(7)(10)\left(\frac{21}{30}\right)=\boxed{49}$.
prompt.content: <|im_start|>system
  You are a helpful assistant.<|im_end|>
  <|im_start|>user
  The operation @ is defined as $\frac{m}{n}@\frac{p}{q} = (m)(p)\left(\frac{q}{n}\right)$ for simplified fractions $\frac{p}{q}$.  What is the simplified value of $\frac{7}{30}@\frac{10}{21}$?
  Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
  <|im_start|>assistant
  
prompt.role: user
extra_info.answer: 49
extra_info.question: The operation @ is defined as $\frac{m}{n}@\frac{p}{q} = (m)(p)\left(\frac{q}{n}\right)$ for simplified fractions $\frac{p}{q}$.  What is the simplified value of $\frac{7}{30}@\frac{10}{21}$?
extra_info.split: test