Which of the following fractions is the greatest?
AnswerCorrect option: B. $\frac56$
In order to find the greatest fraction among the above given fractions, we will convert all the fractions to an equivalent fraction with denominator equal to the $LCM$ of their denominator.
$\begin{array}{c|c} 2&7,6,9,8\\\hline2&7,3,7,4\\\hline2&7,3,9,2\\\hline 3&7,3,9,1\\\hline3&7,1,3,1\\\hline7&7,1,1,1\\\hline&1,1,1,1\end{array}$
So, $LCM$ of denominator i.e. $LCM$ of $7, 6, 9$ and $8 = 2 \times 2 \times 2 \times 3 \times 3 \times 7 = 504$
Now, we converty the givn fraction to equivalent fractions with denominator 504.
$\frac{5\times72}{7\times72}=\frac{360}{504},\frac{5\times84}{6\times84}=\frac{420}{504}$
$\frac{5\times56}{9\times56}=\frac{280}{504},\frac{5\times63}{8\times63}=\frac{315}{504}$
Clearly, $\frac{420}{504},$ i.e. $\frac56$ is greatest.