The pie chart above shows the statistical distribution of 80 students in five subjects in an examination. Calculate how many student offer Mathematics.
A.
30
B.
11
C.
50
D.
20
Correct answer is B
5x° + (16x - 24)° + 5x° + (4x + 12)° + (6x + 12)° = 360°
36x° - 24 + 12 + 12 = 360°
36x° = 360°
x° = \(\frac{360°}{36}\)
= 10°
Thus, the angle of sector representing Mathematics is 5 x 10° = 50°. Hence the number of students who offer mathematics is
\(\frac{50}{360} \times 80 \approx 11\)