IBPS RRB Officer Scale 1 Exam 12 Sep 2020 Prelims Shift 1 Paper

Given below are two quantities named I and II. Based on the given information, you have to determine the relation between the two quantities. You should use the given data and your knowledge of Mathematics to choose among the possible answers.
Quantity I: A and B completes the work in 15 days while working together. The ratio of their time is 3 : 5. In how many days B alone can complete the work.
Quantity II: 45 days