The cost of 50 bags of rice is given as 20,000 rupees, with each bag weighing 15kg. Now, we need to determine the cost of 30 bags of rice, each weighing 10kg.

To solve this problem, we can use the concept of ratios and proportions. Let’s set up a proportion to find the cost of 30 bags of rice:

Let’s assume x as the cost of 30 bags of rice.

The proportion can be set up as follows:

(50 bags) : (30 bags) = (20,000 rupees) : (x rupees)

Now, let’s solve for x using cross-multiplication. Multiply the numerator of the first ratio (50 bags) by the denominator of the second ratio (x rupees), and multiply the denominator of the first ratio (30 bags) by the numerator of the second ratio (20,000 rupees):

50 * x = 30 * 20,000

Simplifying further:

50x = 600,000

To isolate x, divide both sides of the equation by 50:

x = 600,000 / 50

x = 12,000

Therefore, the cost of 30 bags of rice, each weighing 10kg, would be 12,000 rupees.

In conclusion, based on the given information, we used the concept of ratios and proportions to determine that the cost of 30 bags of rice, each weighing 10kg, is 12,000 rupees. This approach allows us to find the cost of a different quantity of bags while considering the change in weight per bag.