The account balance on april 1st is $60.15. on april 15th a payment of $51.00 is made. on april 25th a purchase of $91.27 is made. what is the finance charge if the annual rate is 18%? what is the new account balance? (use the unpaid balance method.) finance charge = new account balance =

there is only one way to arrange all the eight relative to each other because they are not distinct. we have

now there are nine places to place an (and not more than one in one place).   because we have four symbols, we need to choose four of these nine places to insert an . order does not matter because the are not distinct.

thus there are 1 · c(9,4) ways, or, if we calculate it,

thus there are 126 ways to form such "words."