The time t required to drive a certain distance varies inversely with the speed r. if it takes 2 hours to drive the distance at 30 miles per hour, how long will it take to drive the same distance at 35 miles per hour?

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?