Question:
If the cost of 93 m of a certain kind of plastic sheet is Rs 1395, then what would it cost to buy 105 m of such plastic sheet?
Solution:
Let the cost of the plastic sheet per metre be Rs $x$.
If more sheets are bought, the cost will also be more.
Therefore, it is a direct variation.
We get:
$93: 105=1395: x$
$\Rightarrow \frac{93}{105}=\frac{1395}{x}$
Applying cross muliplication, we get:
$x=\frac{105 \times 1395}{93}$
$=1575$
Thus, the required cost will be Rs 1,575 .