Question

If $a:b=5:7$ and $b:c=6:11$, then $a:b:c=$

• A. $55:77:66$
• B. $30:42:77$
• C. $35:49:42$
• D. $50:48:49$

Answer 1

The correct option is B $30:42:77$

$b:c=\left(\begin{array}{c}6\times \frac{7}{6}\end{array}\right):\left(\begin{array}{c}11\times \frac{7}{6}\end{array}\right)=7:\frac{77}{6}$
$a:b:c=5:7:\frac{77}{6}=30:42:77$