Question

If x:y = 2:3 and y:a = 5:7, find x:y:z

Answer 1

Answer:

$\frac{x}{y} = \frac{2}{3} = \frac{2 \times 5}{3 \times 5} = \frac{10}{15} \\ \frac{y}{z} = \frac{5}{7} = \frac{5 \times 3}{7 \times 3} = \frac{15}{21}$

so, x : y : z = 10 : 15 : 21