Question

Re-arrange the given fractions in descending order:

$\frac{3}{7},\frac{4}{21},\frac{11}{42},\frac{13}{28}$

Answer 1

$\text{LCM of}7,21,42\text{and}28=2\times 2\times 3\times 7=84$

$\frac{3}{7}=\frac{3\times 12}{7\times 12}=\frac{36}{84}(84÷7=12)$

$\frac{4}{21}=\frac{4\times 4}{21\times 4}=\frac{16}{84}(84÷21=4)$

$\frac{11}{42}=\frac{11\times 2}{42\times 2}=\frac{22}{84}(84÷42=2)$

$\frac{13}{28}=\frac{13\times 3}{28\times 3}=\frac{39}{84}(84÷28=3)$

$\text{Since}39>36>22>16$

$\frac{39}{84}>\frac{36}{84}>\frac{22}{84}>\frac{16}{84}$

$\frac{13}{28}>\frac{3}{7}>\frac{11}{42}>\frac{4}{21}$