In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: if it takes 70 workers 3 hours to disassemble the exhibition rides at a small amusement park , how many hours would it take 30 workers to do this same job ?
Options: a ) 40 / 3 , b ) 11 , c ) 7 , d ) 7 / 3 , e ) 9 / 7
c