Question:
The ratio of the number of marbles Ryan had to the number of marbles Audrey had at first was 2 : 7. After Ryan bought another 20 marbles and Audrey gave away 80 marbles, the ratio of the number of marbles Ryan had to the number of marbles Audrey had became 1 : 3. How many marbles did Audrey have at first?
Solution:
![P6 / Henry Park / 2019 / SA2 / Paper 2 – Q07 [3 marks]](https://i0.wp.com/sgprimaths.com/wp-content/uploads/2020/06/P6_Henry_Park_2019_Prelims_Paper2_Q07-Qns.jpg?resize=400%2C260&ssl=1)
![P6 / Nan Hua / 2019 / SA1 / Paper 2 – Q05 [2 marks]](https://i0.wp.com/sgprimaths.com/wp-content/uploads/2020/05/P6_Nan_Hua_2019_SA1_Paper2_Q05-Qns.jpg?resize=400%2C260&ssl=1)