Take one bag from the first pile, two bags from the second pile, ..., 10 bag from the 10 pile, and weigh them together.

If the weighed weight is 27500g compared with 55x500.

If 50 grams is missing, it is the first batch of unqualified products.

If it is less than100g, the second pile is unqualified.

....

If it is less than 500g, 10 pile is unqualified.