Subject: mathqa
Question: together , 15 type a machines and 7 type b machines can complete a certain job in 4 hours . together 8 type b machines and 15 type c machines can complete the same job in 11 hours . how many hours e would it take one type a machine , one type b machine , and one type c machine working together to complete the job ( assuming constant rates for each machine ) ?
Option: 
A: 60 hours
B: 30 hours
C: 44 hours
D: 22 hours
Answer: C