Stats. Normal distribution. pls show step solution

Example 7 The marks in a 2007 IB examination were normally distributed with mean 51 and standard deviation 13. If a candidate is selected at random, find the probability that this student scores more than 60 marks. E If two candidates are selected at random, find the probability that both of them score between 45 and 65 marks inclusive. (iii) If three candidates are selected at random, find the probability that one of them score more than 60 marks and the other two score less than 60 marks. If 8 % score A, find the least mark for grade A, giving your answer correct to 1 decimal place