It takes printer A 4 more minutes more 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 100 pages?  Choose one
A) 12  B) 18  C) 20  D) 24  E) 30
If it takes 4 more minutes for A to print 40 pages than it takes B,   it takes 5 more minutes for A to print 50 pages than it takes B.   Thus if b is the number of minutes than B takes to print 50 pages,   we can write:   1/b+1/(b+5)=1/6 (since in 1 minute, they print 1/6th of the 50 page job)   6(2b+5)=b(b+5)   b^2-7b-30=0   (b-10)(b+3)=0   b=10   Thus it takes A 15 minutes to print 50 pages and   15*100/50= 
<gadget id="calculator">  15*100/50</gadget>
<output>30</output>
30 minutes to print 100 pages (ANSW30R 30)
<result>E</result>
It takes printer A 4 more minutes more 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 100 pages?