Two machines, Y and Z, work at constant rates producing identical items. Machine Y produces 30 items in the same time Machine Z produces 38 items. If machine Y takes 19 minutes to produce a batch of items, how many minutes does it take for machine Z to produce the same number of items?
Select:  A) 6  B) 9  C) 9 1/2  D) 15  E) 13 1/2
rate z/rate y=38/30   time z/time y=30/38   30/38*19= 
<gadget id="calculator">30/38*19</gadget>
<output>15</output>
15 minutes   15
<result>D</result>
Two machines, Y and Z, work at constant rates producing identical items. Machine Y produces 30 items in the same time Machine Z produces 38 items. If machine Y takes 19 minutes to produce a batch of items, how many minutes does it take for machine Z to produce the same number of items?