Elena and her husband Marc both drive to work. Elena’s car has a current mileage (total distance driven) of 11,000 and she drives 15,000 miles more each year. Marc’s car has a current mileage of 24,000 and he drives 8,000 miles more each year. Will the mileages for the two cars ever be equal?

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?