(a) Simplify, without using tables or calculator : \(\frac{\frac{3}{4}(3\frac{3}{8} + 1\frac{5}{8})}{2\frac{1}{8} - 1\frac{1}{2}}\).
(b) Given that \(\log_{10} 2 = 0.3010\) and \(\log_{10} 3 = 0.4771\), evaluate, correct to 2 significant figures and without using tables or calculator, \(\log_{10} 1.125\).
Show Answer Show Explanation Explanation (a) \(\frac{\frac{3}{4}(3\frac{3}{8} + 1\frac{5}{8})}{2\frac{1}{8} - 1\frac{1}{2}}\) \(\frac{3}{4}(3\frac{3}{8} + 1\frac{5}{8}) = \frac{3}{4}(\frac{27}{8} + \frac{13}{8})\) = \(\frac{3}{4}(\frac{40}{8})\) = \(\frac{15}{4}\) \(2\frac{1}{8} - 1\frac{1}{2} = \frac{17}{8} - \frac{3}{2}\) = \(\frac{17}{8} - \frac{12}{8}\) = \(\frac{5}{8}\) \(\therefore \frac{\frac{3}{4}(3\frac{3}{8} + 1\frac{5}{8})}{2\frac{1}{8} - 1\frac{1}{2}} = \frac{15}{4} \div \frac{5}{8}\) = \(\frac{15}{4} \times \frac{8}{5}\) = \(6\) (b) \(\log_{10} 2 = 0.3010 ; \log_{10} 3 = 0.4771\) \(\log_{10} 1.125 = \log_{10}(\frac{1125}{1000})\) (Dividing through with 125) = \(\log_{10} (\frac{9}{8})\) = \(\log_{10} 9 - \log_{10} 8\) \(\log_{10} 9 = \log_{10} 3^{2} = 2\log_{10} 3 = 2 \times 0.4771 = 0.9542\) \(\log_{10} 8 = \log_{10} 2^{3} = 3\log_{10} 2 = 3 \times 0.3010 = 0.9030\) \(\therefore \log_{10} (\frac{9}{8}) = 0.9542 - 0.9030 = 0.0512\) \(\approxeq 0.051\) ( 2 significant figures)