So lets start with P, that is our principal or amount of money we start with, and we want to multiply it by our rate, or r , which is 3.5, so we would do 5000 x 0.035 to get 175, then we multiply that by our time or t, which is 4 years, so 175 x 4 = 700 dollars :D
I first took away 60 from 195, as she already had 60 points. Than we were left with 135 points and since she gets 13.5 points every time she visits, I divided 135 by 13, which gives us 10.