Question 1125358
Why 15 unit multipliers?  Fifteen would seem excessive.


-

{{{1000000*yard^3*3^3*(feet/yard)^3*12^3(inch/feet)^3*2.54^3(cm/inch)^3*(1/100)^3(meter/cm)*(1/1000)^3*(kilometer/meter)^3}}}


{{{1000000*27*1728*(2.54)^3(1/1000000)(1/1000000000)*kilometer^3}}}


0.00076455485 cubic kilometers


(!)


-
Notice that I only used FIVE unit multipliers.  If each were only counted once per dimension, then since each is used three times, this makes for 5*3=15 total unit multipliers; or five of them each used three times.