Answer:
Below.
Explanation:
To find the number of students in each grade you multiply the marks by the frequency density. The number of students is given by the area under the rectangles.
So to find the number of students with grade U (< 160) it is:
120 * 0.2 + 40*0.5
= 24 + 20
= 44.
The number for Grade E
= (200 - 160) * 0.5
= 40 * 0.5
= 20.
The others can be found in the same way.