6*. [Maximum mark: 6] [with GDC] $1000 is invested at the beginning of each year for 10 years. The rate of interest is fixed at 7.5% per annum. Interest is compounded annually. Calculate, glving your answers to the nearest dollar (a) how much the first $1000 is worth at the end of the ten years; (b) the total value of the investments at the end of the ten years