The value of $2 . \overline{45}+0 . \overline{36}$ is
(a) $\frac{67}{33}$
(b) $\frac{24}{11}$
(c) $\frac{31}{11}$
(d) $\frac{167}{110}$
Let $x=2 . \overline{45}=2.4545 \ldots \quad \ldots(1)$
Multiplying both sides by 100, we get
$100 x=245 . \overline{45} \quad \ldots \ldots(2)$
Subtracting (1) from (2), we get
$100 x-x=245 . \overline{45}-2 . \overline{45}$
$\Rightarrow 99 x=245-2=243$
$\Rightarrow x=\frac{243}{99}$
$\therefore 2 . \overline{45}=\frac{243}{99}$
Let $y=0 . \overline{36}=0.3636 \ldots . \quad \ldots .(3)$
Multiplying both sides by 100, we get
$100 y=36 . \overline{36} \quad \ldots \ldots(4)$
Subtracting (3) from (4), we get
$100 y-y=36 . \overline{36}-0 . \overline{36}$
$\Rightarrow 99 y=36$
$\Rightarrow y=\frac{36}{99}$
$\therefore 0 . \overline{36}=\frac{36}{99}$
So, $2 . \overline{45}+0 . \overline{36}=\frac{243}{99}+\frac{36}{99}=\frac{243+36}{99}=\frac{279}{99}=\frac{31}{11}$
Hence, the correct answer is option (c).