Final answer:
Dr. Pepper's market share is 20%.
Step-by-step explanation:
Dr. Pepper's market share can be calculated by dividing its market size by the total market size and multiplying by 100.
Market share = (Dr. Pepper's market / Total market) * 100
Therefore, Dr. Pepper's market share is:
(10 Billion / 50 Billion) * 100 = 20%.