Working alone, machine X can manufacture 1,000 nails in 10 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 correct option:
A) 3 9/17
B) 5 1/3
C) 2
D) 7 1/5
E) 8 4/7
rate of machine x = 1000/10   (1000/10 + y)5=1000   y=500/5= 
<gadget id="calculator">500/5</gadget>
<output>100</output>
100   100 * t= 1000   t=1000*1/500   C. 2
<result>C</result>
Working alone, machine X can manufacture 1,000 nails in 10 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?