"If it takes 6 printing presses 4 hours to print 5000 newspapers, how long should it take 3 presses to print 3000 newspapers?"
rate = 5000/(6*4) newspapers per press per hour
rate = 3000/(3*t) newspapers per press per hour
Hence: (3000/(3*t) = 5000/(6*4) so t = 24/5 hours (or t = 4.8 hours)