1. number 5 added to three times the product of M and N. 2. product of number Y and Z subtracted from 10.
3. sum of number X and Y subtracted from their products.
4. workings pls

Amanufacturer knows that their items have a normally distributed lifespan, with a mean if 9.1 years, and standard deviation of 2.9 years. if you randomly purchase one item, what is the probability it will last longer than 10 years?