Question

a:b=9:10 b:c=4:6 a:c​

Answer 1

$\frac{a}{b} = \frac{9a}{10} \\ b = \frac{10}{9} \\ \\ \frac{b}{c} = \frac{4}{6} \\ b = \frac{4c}{6}$

Therefore,

$\frac{9a}{10} = \frac{4c}{6} \\ \frac{a}{c} = \frac{4}{6} \times \frac{10}{9} \\ \frac{a}{c} = \frac{40}{54} = \frac{20}{27}$