Working alone, machine X can manufacture 1,000 nails in 16 hours. Working together, machines X and Y can manufacture 1,000 nails in 5 hours. How many hours does it take machine Y to manufacture 1,000 nails working alone?	Choose the most appropriate option
A) 3 9/17
B) 5 1/3
C) 7
D) 7 3/11
E) 8 4/7
rate of machine x = 1000/16   (1000/16 + y)5=1000   y=200-125/2=275/2   275/2 * t = 1000   t=7 3/11   D. 7 3/11
<result>D</result>
Working alone, machine X can manufacture 1,000 nails in 16 hours. Working together, machines X and Y can manufacture 1,000 nails in 5 hours. How many hours does it take machine Y to manufacture 1,000 nails working alone?