After two bites, the weight of the hamburger is recorded at 160g.
Each bite removes 20% of the burger's total weight, so to uncover the weight prior to the bites, we calculate it based on the percentage that remains.
The initial weight stands at 160g. Given that 20% of the weight was lost during a bite, we should divide this weight by the remaining percentage after the bite:

After a bite, 80% of the burger is what remains. Convert this percentage into a decimal by dividing it by 100:

Now, let's divide the original weight by this figure:

Before the second bite, the weight of the hamburger was 200g.
The same method will apply for the first bite. Initially, it weighed 200g, with 80% still intact after the initial bite. Since 80% converts to 0.8 in decimal form, divide 200 by 0.8:

Thus, the original weight of the hamburger prior to any bites was
250 grams.