(2,20) means that the 2 is 2 hours and 20 is 20$. so there both 20$ for 2 hours only the same price. like it says. so, the dunk tank and the bounce house are the same price (20$) for the same amount of time (2 hours).
what type of question is thiss
Given that you invest $150 at 7% interest compounded annually. Now we need to find about in how many years will you have $400. Then round the answer ot the nearest tenth of a year.
So plug the given values into compound interest formula.
Which is approx 14.5 years.