subash can copy 50 pages in 10 hrs.subash and prakash together can copy 300 pages in 40 hours.in how much time prakash can copy 30 pages. Select
A) 8 B) 10 C) 12 D) 14 E) 16
subhas 's 1 hr copy page=50/10= 
<gadget id="calculator">50/10</gadget>
<output>5</output>
5 page   (subhas+prakash)'s 1 hr copy page=300/40= 
<gadget id="calculator">300/40</gadget>
<output>15/2 = around 7.5</output>
7.5 page   from above prakash's 1 hr copy page= 2.5 page   so time taken in 30 page's copy =(30/2.5)= 
<gadget id="calculator">(30/2.5)</gadget>
<output>12</output>
12 hrs   ANSWER:12
<result>C</result>
subash can copy 50 pages in 10 hrs.subash and prakash together can copy 300 pages in 40 hours.in how much time prakash can copy 30 pages.