(21 * 1.10) / 3 = 23.10/3 = 7.7....so each friend has to pay $ 7.70
could you specify your question a bit more?
You divide 500 by $50 to get 10; the school sold 10 yearbooks that year if you’re looking for that as an answer.
Object speed * time= rate
4/5 miles in half hour
4/5(2)=8/5 mph