Maria, an experienced shipping clerk, can fill a certain order in 11 hours. Felipe , a new clerk, needs 14 hours to do the same job. Working together, how long will it take them to fill the order? Solution Maria can fill in 11 hrs --- 1order So, Maria can fil in 1 hr --- 1/11 of order Felipe can fill 14 hrs --- 1order Felipe can fill in 1/14 of order If together work they can fill in 1hr = 1/11 +1/14 = 25/11*14 = 25/154of an order Now they can fill i 1 complete order in 154/25 = 6.16 hrs.