Question

Suppose $A,B,C$ have $Rs.a,Rs.b,Rs.c$ respectively. If $a:b=4:5,b:c=2:3$ and $a=800$, find $c$.

Answer 1

$a:b=4:5$

$\Rightarrow \frac{a}{b}=\frac{4}{5}$

We know that $a=800$

$\Rightarrow \frac{800}{b}=\frac{4}{5}$

Cross multiply

$\Rightarrow 4b=40000$

$\Rightarrow b=\frac{40000}{4}$

$\Rightarrow b=10000$

From the question $b:c=2:3$

$\Rightarrow \frac{b}{c}=\frac{2}{3}$

We know that $b=1000$

$\Rightarrow \frac{1000}{c}=\frac{2}{3}$

Cross multiply

$\Rightarrow 2c=3000$

$\Rightarrow c=\frac{3000}{2}$

$\Rightarrow c=1500$