In the economy mode, a printer prints twice as fast as in the optimal quality mode. If after working for 20 minutes in the optimal quality mode and 40 minutes in the economy mode the printer printed 120 pages, how long would it take the printer to print 120 pages in the optimal quality mode?
(C) 2008 GMAT Club - m14#31
* 35 minutes
* 40 minutes
* 50 minutes
* 1 hour 20 minutes
* 1 hour 40 minutes
guys, im trying to solve with:
2x/40 +x/20 = 1/120
something is wrong and i cant tell exactly what. Any advice?
am i too much tired????? i cant detect my mistake
Optimal mode - x pages per minute;
Economy mode - 2x pages per minute;
Given: 20*x+40*2x=120 --> x=1.2 --> to print 120 pages in optimal mode printer will need 120/1.2=100 minutes = 1 hour 40 minutes.