It takes printer A 4 more minutes than printer B to print 40 pages. Working together, the two printers can print 50 pages in 6 minutes. How long will it take printer A to print 80 pages? Choose the correct choice from the following
A) 12  B) 18  C) 20  D) 24  E) 30
We need time taken by printer A to print 80 pages. (Let's say this is 'a' mins)   We know A takes 4 more mins for 40 pages so it will take 8 more minutes for 80 pages.   Together, they print 50 pages in 6 mins so they will print 80 pages in 6*50/80 = 48/5 mins   Now, make your sum of rates equation:   1/a + 1/(a - 8) = 5/48   Now look at the options and substitute here. First check out the straight forward options.   Say, a = 12   1/12 + 1/4 = 4/12 Nope   I will not try 18 and 20 because (18, 10) and (20, 12) doesn't give me 48, the denominator on right hand side.   I will try 24 instead.   1/24 + 1/16 = 5/48 Yes.   Answer is 24.   ANSWER:24
<result>D</result>
It takes printer A 4 more minutes than printer B to print 40 pages. Working together, the two printers can print 50 pages in 6 minutes. How long will it take printer A to print 80 pages?