All robots are working simultaneously, so each robot takes 10 minutes to do their orders. They are all identical, so they take an equal amount of time to do each order, meaning 20 ÷ 5 = 4. Each robot takes 10 minutes to do 4 orders.
If there are eight robots working for 60 minutes, each robot can make six times as many orders, compared to when they were working for 10 minutes. 4 x 6 = 24. There are eight robots, so 24 x 8 = 192 orders.
60/45 = $0.75 It costs $0.75 to make each valentine so if they were sold for 75 cents then that would result in a profit of zero if all the valentines were sold.