Question: Two workers can complete a job in 20 days and 30 days respectively. If they work together for 10 days, how much of the job is left?
Options:
Correct Answer: 1/3
Solution:
Worker 1\'s rate = 1/20, Worker 2\'s rate = 1/30. Combined rate = 1/20 + 1/30 = 1/12. In 10 days, they complete 10/12 = 5/6 of the job, leaving 1/6.