Working together, printer A and printer B would finish the task in 20 minutes. Printer A alone would finish the task in 60 minutes. How many pages does the task contain if printer B prints 4 pages a minute more than printer A ?
Choose the correct choice from the following answers:
A) 120
B) 180
C) 240
D) 280
E) 340
20*A + 20*B = x pages   in 20 mins printer A will print = 20/60 * x pages = 1/3*x pages   thus in 20 mins printer printer B will print x - 1/3*x = 2/3*x pages   Also it is given that printer B prints 4 more pages per min that printer A. In 20 mins printer B will print 80 more pages than printer A   thus 2/3*x - 1/3*x = 80 =&gt; x = 240 pages   Answer: 240
<result>C</result>
Working together, printer A and printer B would finish the task in 20 minutes. Printer A alone would finish the task in 60 minutes. How many pages does the task contain if printer B prints 4 pages a minute more than printer A ?