Question

If the cost of a dozen soaps is $\text{Rs}460.80$, what will the cost of:
$15$ soaps $?$

Answer 1

Find the cost of $15$ soaps

Given: Cost of one dozen soaps $=\text{Rs}460.80$

We know that,
One dozen $=12$

$\Rightarrow$ Cost of $12$ soaps $=\text{Rs}460.80$

$\Rightarrow$ Cost of $1$ soap $=\frac{460.80}{12}$

$=\frac{460.80\times 100}{12\times 100}=\frac{46080}{1200}$

$=\frac{4\times 4\times 4\times 4\times 4\times 3\times 3\times 5}{4\times 3\times 10\times 10}$
$=\frac{384}{10}=38.4$

Thus Cost of one soap $=\text{Rs}38.4$

$\therefore$ cost of $15$ soaps $=15\times 38.4=\text{Rs}576$

Hence, the cost of $15$ soap is $\text{Rs}.576$.