This is not a full question. If you were given the amount at the begining of 1970 (we'll call it x) and the amount at the end of 1980 (we'll call it y), we should solve them accordingly:
y-x=? (calling the answer a)
a/y=%(not answer yet, call this b)
b+100=answer
I’m guessing 2 cups or something idk
The original price would be $92.38
.25(73.90)=18.475
18.475+73.90 would be 92.38
Since they are congruent, corresponding sides and angles are also congruent
AB=DE