In 80 minutes, the faster machine printed 360 more copies than the slower one.

Since they print the same number of copies in the end,

After 80 minutes, the slower machine still has 360 copies left to print, while the faster machine has already stopped since it's already done printing.

And since the slower machine takes 100 minutes to print all copies, there are still 20 more minutes to go.

So the machine has to print 360 copies in these 20 minutes.


360 ÷ 20 = 18

So we now know that the slower machine prints 18 copies a minute.

Number of copies in 100 minutes
= 18 x 100
= 1800

Since the faster machine printed the same number in the end,

Total copies by both machines
= 1800 x 2
= 3600

I was thinking question asked for 80 mins printing quantity....

Oh that would be 3600 - 360 = 3240

I am not sure too....

The answer should be 3600. I've seen this question (both online and offline) quite a few times.

The question also says the machines 'took' the stated amount of minutes to print same number of copies instead of 'takes' so it's in the past tense which mean it happened already. So the question just asking how many printed in total at the end.

Yes. Made sense... is 3600