In a class of 60 pupils, the statistical distribution of the numbers of pupils offering Biology, History, French, Geography and Additional mathematics is as shown in the pie chart. How many pupils offer Additional Mathematics?
Attached Figure / Diagram
A
15
B
10
C
18
D
12
E
20
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
(2x - 24)^\circ + (3x - 18)^\circ + (2x + 12)^\circ + (x + 12)^\circ + x^\circ = 360^\circ
9x = 360^\circ + 18^\circ
x = \(\frac{378}{9}\)
= 42^\circ, if x = 42^\circ, then add maths = \(\frac{2x - 42}{360}\) x 60
= \(\frac{2 \times 42 - 24}{360}\) x 60
= \(\frac{84 - 24}{6}\)
= 10
Source: Myschool Past Questions Archive (Record #32765)