Question

Solve the following equation and get the value of $z$.
$\frac{z}{z+15}=\frac{4}{9}$

• A. 15
• B. 12
• C. 11
• D. 8

Answer 1

The correct option is B 12

$\frac{z}{z+15}=\frac{4}{9}$
⇒ $9z=4(z+15)$ [After doing cross-multiplication]
⇒ $9z=4z+60$
⇒ $9z-4z=60$
⇒ $5z=60$
⇒ $z=\frac{60}{5}$
⇒ $z=12$