Question

Set up a table and solve the following problems. Use unitary method to verify the answer.
If the cost of $93$ of a certain kind of plastic sheet is $Rs.1395$, then what would it cost to buy $105m$ of such plastic sheet?

Answer 1

Draw a table and find the cost

Given: Cost of $93m$ of sheet $=Rs.1395$

Let the cost of $105m$ of sheet be $Rs.x$

Sheet length $\left(m\right)$	$93$	$105$
Cost $(Rs.)$	$1395$	$x$

Clearly, the larger the length of the sheet, greater will be the cost of the sheet. So, it is a case of direct variation.

Therefore, ratio of length of the sheet to the cost would be same for both the cases.

$\Rightarrow \frac{93}{1395}=\frac{105}{x}$

$\Rightarrow x=105\times \frac{1395}{93}$

$\Rightarrow x=1575$

Hence, the cost of $105m$ sheet is $Rs.1575$

Verify using unitary method

Given: Cost of $93m$ of sheet $=Rs.1395$

$\Rightarrow$ Cost of $1m$ of the sheet $=\frac{1395}{93}$

$=Rs.15$

$\Rightarrow$ Cost of $105m$ of the sheet $=105\times 15$
$=Rs.1575$

Thus, the cost of $105m$ sheet is $Rs.1575$.

Thus, the cost of $105m$ sheet is $Rs.1575$.

Hence, verified.