Find $n$ if $\gcd(n,40) = 10$ and $\mathop{\text{lcm}}[n,40] = 280$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Find $n$ if $\gcd(n,40) = 10$ and $\mathop{\text{lcm}}[n,40] = 280$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
70
Find $n$ if $\gcd(n,40) = 10$ and $\mathop{\text{lcm}}[n,40] = 280$.
train