Otto the octopus needs $$2$$ tentacles to juggle up to $$3$$ balls.  If Otto uses all $$8$$ tentacles, Otto can juggle up to  balls. 
Overseas Competition->Knowledge Point->Word Problem Modules->Unitary Method Problems->Applying Multiplication and Division
Otto needs $$2$$ tentacles to juggle up to $$3$$ balls. Using $$8=4\times2$$ tentacles, Otto can juggle up to $$4\times3 = 12$$ balls. 