HELP PLEASE Which of the following is an example of active transport in a cell?
Choose 1
Oxygen entering the cell without the use of energy
B
Sodium moving out of the cell against its concentration gradient
Calcium passing through channel proteins, from a high to low concentration
Enzymes spreading evenly through cytoplasm

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

Ann and betty together have $60 ann has $9 more than twice betty’s amount how much money dose each have

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