4) The run time for written C-Programmes for Gauissian elimination follows a normal distribution with a mean of 36 minutes and a standard deviation of 11 minutes. For a C-Programme chosen from Gaussian elimination files at random, find the probability that the run time will be

a) less than 51 minutes (2 marks)

b) more than 60 minutes (2 marks)

c) between 41 and 56 minutes (5 marks)

d) between 12 and 26 minutes