<|system|>
Find the sum of all positive divisors of $50$ that are also divisors of $15$.</s>.
<|user|>
Can you answer based on context?
<|assistant|>
The positive factors of $50$ are $1, 2,5, 10, 25, 50$.  Of these, only $ 1$ and $ 5$ divide $15$.  Their sum is $1+5 = 6$.