Study the following graph and answer the question that follows.
What is the ratio of the average number of students appeared from schools A, B and D to the total number of students passed from schools B and D?
Number of students appeared and passed an examination from schools A, B, C and D in 2021.
1
2 ∶ 3
2
5 ∶ 8
3
3 ∶ 5
4
5 ∶ 6