Question

it takes an HP laserjet 1300 printer 10 minute longer to complete a 600 page print job by itself than it takes an HP laserjet 2420 to complete the same job itself. Together the two printers can complete the job in 12 min. How long does it takes for each printer to do the job alone? What is the speed in pages per min of each printer?

Answer 1

If the 2420 does it in x minutes, then

1/12 = 1/x + 1/(x+10)
x = 20

Answer 2

thanks steve