Performance of 1800 students in grades has been shown in the following pie chart. The number of students getting grade B is what percentage of the number of students getting grade A?
In the given figure, ABCD is a cyclic quadrilateral. the angle bisector of ∠D and ∠C meets at point E. If the ∠DEC = 72∘, then find the value of (α + β).
Marks | number of students |
1 - 20 | 10 |
20 - 40 | 40 |
40 - 60 | 15 |
60 - 80 | 12 |
80 - 100 | 30 |
What is the ratio of the number of student between 20-40 and 80-100 marks?