Question

$l\left(AB\right):l\left(BC\right)=3:2$. Find $AC$ if $l\left(AB\right)=7.2cm.$

• A. $6cm$
• B. $12cm$
• C. $18cm$
• D. $24cm$

Answer 1

Answer: (B)

$12cm$

Given that:

$l\left(AB\right):l\left(BC\right)=3:2$

$l\left(AB\right)=3x$ and $l\left(BC\right)=2x$

Then,

$3x=7.2$ ........ $\left[l\right(AB)=7.2cm]$

$x=2.4$

Hence,

$l\left(BC\right)=2\times 2.4=4.8cm$

Also,

$AC=AB+BC$

$AC=7.2+4.8=12cm$