Answer:
1. 19 students
2. 13 students
3. 72°
Step-by-step explanation:
1. The diagram shows that mark A have 10% of students and mark B have 37.5% of students, so mark A or B have
[tex]10\%+37.5\%=47.5\%[/tex] of 40 students.
Find 47.5% of 40:
[tex]40\cdot 0.475=19[/tex] students
2. The diagram shows that mark D have 17.5% of students and mark F have 15% of students, so mark D or F have
[tex]17.5\%+15\%=32.5\%[/tex] of 40 students.
Find 32.5% of 40:
[tex]40\cdot 0.325=13[/tex] students
3. Mark C have 20% of students. Since
[tex]20\%=\dfrac{1}{5},[/tex]
then the central angle is [tex]\frac{1}{5}[/tex] of the full angle with the measure of 360°. Hence, the central angle has the measure of
[tex]\dfrac{1}{5}\cdot 360^{\circ}=72^{\circ}[/tex]
