In the first 2 hours after Meadow's self-service laundry opens, m large washing machines and n small washing machines are in con
tinual use. Including the time for filling and emptying the washing machines, each load of laundry takes 30 minutes in a large washing machine and 20 minutes in a small washing machine. What is the total number of loads of laundry done at Meadow's self-service laundry during this 2-hour period?
we have that m = amount of time used by the large washing machine to wash a load of clothes and n = amount of time used by the small washing machine to wash a load of clothes, so
Nt=m+n=10
where Tt = time frame, Tpm= m' time frame, Tpn = n' time frame and Nt = total number of charges