If it takes Hugo twice the amount of time to fold a medium box than a small box, then he needs 2*3 = <<6=6>>6 seconds for the medium box
If Tom can fold either the small or medium box in 4 seconds, then he's faster at folding the medium box than Hugo because 4s < 6s
If Hugo can fold the small box in 3 seconds, then he's faster at folding the small boxes than Tom because 3s < 4s
Therefore Hugo should fold all small boxes and Tom should fold all the medium ones before doing the other size where they are slower
If there are 2400 small boxes and Hugo can fold 1 box in 3 seconds, then it would take him 2400*3 = <<2400*3=7200>>7200 seconds to fold all boxes
If there are 1800 medium boxes and Tom can fold 1 box in 4 seconds, then it would take him 1800*4 = <<1800*4=7200>>7200 seconds to fold all medium boxes
Given that they need the same amount of time to fold all boxes, and are doing it simultaneously they will need 7200 seconds to fold all the boxes
#### 7200