If A = 0.3 12 , B = 0.4 15 and C = 0.30 9 , then what is the value of A + B + C?

Answer: Option B

$$\begin{array}{rl}& A=0.3\overline{12}=\frac{312-3}{990}=\frac{309}{990}\\ & B=0.4\overline{15}=\frac{415-4}{990}=\frac{414}{990}\\ & C=0.30\overline{9}=\frac{309-30}{900}=\frac{279}{900}\\ & A+B+C=\frac{309}{990}+\frac{414}{990}+\frac{279}{900}\\ & =\frac{3090+4140+3069}{9900}\\ & =\frac{10269}{9900}\\ & =\frac{1141}{1100}\end{array}$$