I could use some help with the following:
Jacques is saving for a new car which will cost 29000 dollars. He saves by putting 400 dollars a month into a savings account which gives 0.1% interest per month. After how many months will he be able to buy his car? (assume it does not increase in price)
Soo at the end of the first month, what he has is 400*1.1 + 400; and at the end of the 2nd month this is 840*1.1 + 400 . But I can't really find the way to express this as geometric series. If n is the # of months, r the common ratio it'll be like [400[(r)^n-1]]/(r-1)
..but how exactly? -excuse my amateurishness, its been a while- thanks in advance!