Question 248812
Formula is RT = W


From this formula, you can derive:


T = W/R
and
R = W/T


printing press can print 300,000 cards in 12 hours.


T = 12
W = 300,000
R = W/T = 300,000/12 = 25,000 cards per hour.


older press requires 18 hours to print 300,000 cards.


T = 18
W = 300,000
R = W/T = 16,666.66666667 cards per hour.


working together, their rates will combine.


you get:


T = x
W = 300,000
R = 25,000 + 16,666.66666667 = 41,666.66666667 cards per hour.


When solving for T, formula becomes:


T = W/R


This equation becomes:


T = 300,000/41,666.66666667 = 7.2 hours.


In 7.2 hours, the printing press has completed 25,000 * 7.2 = 180,000 cards.


In 7.2 hours, the old press has completed 16,666.66666667 * 7.2 = 120,000 cards.


total cards produced is 180,000 + 120,000 = 300,000