Question

If $A:B=5:8$ and $B:C=10:13$, find $A:B:C$.

Answer 1

$A:B=5:8$

So,

$\frac{A}{B}=\frac{5}{8}$

$A=\frac{5B}{8}$ ......(1)

$B:C=10:13$

So,

$\frac{B}{C}=\frac{10}{13}$

$C=\frac{13B}{10}$ ......(2)

From (1) and (2),

$A:B:C=\frac{5B}{8}:B:\frac{13B}{10}$

$=\frac{5}{8}:1:\frac{13}{10}$

$=25:40:52$