The volume of cracker boxes are normally distributed, with a mean of 7 oz and a standard deviation of 0.2 oz. If a box is selected at random, What is the probability of getting an amount between that is at least 7.5 oz

Afactory buys 10% of its components from suppliers b and the rest from supplier c. it is known that 6% of the components it buys are faulty. of the components brought from suppliers a,9% are faulty and of the components bought from suppliers b, 3% are faulty. find the percentage of components bought from supplier c that are faulty.