Question

If 4 kg jaggery cost Rs 80, how much will 15 kg jaggery cost?

Answer 1

Cost of 4 Kg jaggery is Rs 80.
Let the cost of 15 Kg jaggery be Rs x.
The given information can be represented in the following table:

Cost of jaggery (in Rs): x	80	x
Weight of jaggery (in Kg): y	4	15

Here, cost of jaggery and weight of jaggery are in direct proportion because the cost of jaggery will increase with an increase in the weight. In direct variation,the ratio of the cost of jaggery to the weight of jaggery must be constant,i.e
$$\begin{gathered} \frac{x_1}{y_1}=\frac{x_2}{y_2} \\ \therefore \frac{80}{4}=\frac{x}{15} \\ x=\frac{80}{4}\times 15=300\mathrm{Rs} \end{gathered}$$
Thus, 15 Kg jaggery will cost Rs 300.