Question

If A : B = 3 : 5 and B : C = 4 : 7 , find A : C .

Answer 1

12 : 35

Step wise Explanation

A : B = 3 : 5

B : C = 4 : 7

LCM of 5 and 4 => 20

$\rm \dfrac{A}{B} = \dfrac{3}{5} \times \dfrac{4}{4} = \color{blue} \dfrac{12}{20}$

$\rm \dfrac{B}{C} = \dfrac{4}{7} \times \dfrac{5}{5} = \color{lime}\dfrac{20}{35}$

A : B : C = 12 : 20 : 35

A : C = 12 : 35