Find:12+122+123=\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}=21+221+231= A0.625B0.875C1.125D0.785Answer: B. 0.875 Read Explanation: 12+122+123\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}21+221+231=1×52×5+1×254×25+1×1258×125=\frac{1\times5}{2\times5}+\frac{1\times25}{4\times25}+\frac{1\times125}{8\times125}=2×51×5+4×251×25+8×1251×125=510+25100+1251000=\frac{5}{10}+\frac{25}{100}+\frac{125}{1000}=105+10025+1000125=0.5+0.25+0.125=0.5+0.25+0.125=0.5+0.25+0.125=0.875=0.875=0.875 Read more in App