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 / Maris Stella / 2020 / SA2 Prelims / Paper 2 – Q12 [4 marks]](https://i0.wp.com/sgprimaths.com/wp-content/uploads/2021/12/P6_SA2_2020_Maris_Stella_Paper2_Q12-Qns.jpg?resize=400%2C260&ssl=1)
![P6 / Red Swastika / 2020 / SA2 Prelims / Paper 2 – Q09 [3 marks]](https://i0.wp.com/sgprimaths.com/wp-content/uploads/2020/11/P6_Red_Swastika_2020_SA2_Paper2_Q09-Qns.jpg?resize=400%2C260&ssl=1)