Suppose that the amount of algae in a pond doubles every 6 hours. If the pond initially contains 50 pounds of algae, how much algae will be in the pond after 18 hours?
A. 400
B. 10,800
C. 300
D. 600
Every 6 hours, the amount of algae doubles. Therefore, after 18 hours, the algae will have doubled three times:
First doubling: 50 x 2 = 100 pounds
Second doubling: 100 x 2 = 200 pounds
Third doubling: 200 x 2 = 400 pounds
Therefore, the answer is A. 400.
To solve this problem, we can use the concept of exponential growth.
Since the amount of algae doubles every 6 hours, we can calculate the number of doublings that occur in 18 hours by dividing the total time (18 hours) by the doubling time (6 hours):
Number of doublings = 18 hours / 6 hours = 3 doublings
Now we can find the total amount of algae after 18 hours by multiplying the initial amount (50 pounds) by 2 raised to the power of the number of doublings:
Algae after 18 hours = 50 pounds * 2^3 = 50 pounds * 8 = 400 pounds
Therefore, the correct answer is A. 400