Urgent Help please!!!

(b ) A factory produce highlight pens whose diameters are normally distributed with mean and standard deviation of 10mm and 0.1mm respectively. (i ) If a highlight pen is chosen at random, find the probability that its diameter is less than 9.80mm. ( ii ) Find the probability of highlight pen that have diameters between 9.75mm and 10.15mm. (iii ) If a random sample of 10 highlight pens is chosen, find the probability that the mean diameter is exceeding 10.25mm