【Question 5】
Two fat boys weighed the same, and they decided to lose weight together. After three months, Big Fat lost 12 kilograms, and Little Fat lost 7 kilograms. At this point, Big Fat's weight was 80 kilograms less than twice Little Fat's weight. Originally, they each weighed $\qquad$ kilograms.
【Analysis and Solution】
(Method One)
If Erpang (Second Fat) loses 7 kilograms, but Dapang (First Fat) gains $80-12=68$ kilograms; then Dapang's weight is twice that of Erpang;

At this point, Erpang's weight is $(68+7) \div(2-1)=75$ kilograms;
Originally, Erpang's weight was $75+7=82$ kilograms;
That is, Dapang and Erpang originally each weighed 82 kilograms.
(Method Two)
Let Dapang and Erpang originally each weigh $x$ kilograms;
$$
x-12=2(x-7)-80 \text {; }
$$

Solving for $x$ gives $x=82$;
Dapang and Erpang originally each weighed 82 kilograms.