Question

Assume that in 2015, the first edition of a comic book was sold at auction for $1,920,000. the comic book was originally sold in 1942 for $.09.for this to have been true, what was the annual increase in the value of the comic book?

Answer 1

Let
x------------------- > cost comic book sold in 1942--------------> $1,920,000
y------------------- > cost comic book sold in 2015--------------> $0.09
t------------------ > time---------------> (2015-1942)= 73 years
z-----------------> average increase per year

we know that
z={[(x-y)/y]/t}*100
then

z={[(1920000-0.09)/0.09]/73}*100=29,223,743 %

the answer is 29,223,743 %