Question:
Tick (✓) the correct answer:
In the pie chart representing the percentages of students having interest in reading various kinds of books, the central angle of the sector representing students reading novels is 81°. What is the percentage of students interested in reading novels?
(a) 15%
(b) 18%
(c) $22 \frac{1}{2} \%$
(d) $27 \frac{1}{2} \%$
Solution:
(c) $22 \frac{1}{2} \%$
Let the required percentage be $x$. Then we have :
$\left(\frac{x}{100} \times 360\right)=81$
$\Rightarrow \frac{360 x}{100}=81$
$\Rightarrow x=\left(81 \times \frac{100}{360}\right)$
$\Rightarrow x=\frac{45}{2}$
$\Rightarrow x=22 \frac{1}{2}$
Hence, the percentage of students who are interested in reading novels is $22 \frac{1}{2} \%$.