16 (2500U10-1) Examiner only 13. Describe, giving an example, one type of maintenance performed on a computer program. [3] © WJEC CBAC Ltd. (2500U10-1) Turn over. 17 Examiner only 14. Andrew is considering using three different methods for storing positive numbers, using two’s complementation, in a computer system. © WJEC CBAC Ltd. METHOD 1 Store numbers as an integer using an 8 bit register. METHOD 2 Store real numbers in normalised floating-point form, using a 5 bit mantissa and a 3 bit exponent. METHOD 3 Store real numbers in normalised floating-point form, using a 4 bit mantissa and a 4 bit exponent. Calculate the denary range (highest and lowest) of numbers that can be stored by each method. Compare the advantages of representing numbers in integer and floating-point forms. [12] 18 (2500U10-1) Examiner only END OF PAPER © WJEC CBAC Ltd. (2500U10-1) Turn over. 19 © WJEC CBAC Ltd. For continuation only. Examiner only (2500U10-1) 20 © WJEC CBAC Ltd. For continuation only. Examiner only