Ezra spend 60 dollars on gas each week for a period of three weeks. the first week gas was 3 dollars per gallon, the second week it was 4 dollars per gallon, and the third week it was 5 dollars per gallon. how many gallons of gas did ezra purchase in total over the 3 weeks?

The krasnapolski is a top-of-the-line hotel in amsterdam, the netherlands. among their many services, they rent bicycles to guests. the bicycle checkout is open 24 hours per day 7 days per week and has 50 bicycles on hand. on average, 10 guests request a bicycle each day, arriving completely randomly at all times of the day during the spring and summer seasons. guests keep bicycles for four days on average, with a standard deviation of two days. how long does a guest on average have to wait for a bike? a. approximately 24 hours b. approximately 0.033 hours c. approximately 4 days d. approximately 47 minutes