If a quarter kilogram (250 g) of potatoes costs 60 paise, then, assuming the same rate per gram, how many paise will 200 grams of potatoes cost?

Introduction / Context:
This is another unitary-method question involving direct proportion between weight and cost, this time using potatoes instead of carrots. It reinforces your understanding that for a fixed rate per gram, cost changes in direct proportion to weight.

Given Data / Assumptions:
- 250 grams (a quarter kilogram) of potatoes cost 60 paise.
- We must find the cost of 200 grams of potatoes at the same rate.
- The price per gram is constant.

Concept / Approach:
Because cost is directly proportional to quantity when rate per unit is fixed, we can either find the cost per gram and multiply by 200, or simply scale the cost in proportion to the weight ratio 200 / 250. These are equivalent methods and both rely on simple proportionality.

Step-by-Step Solution:
Step 1: Recognise that 250 g of potatoes cost 60 paise.Step 2: Cost per gram = 60 / 250 paise.Step 3: Cost for 200 g = (60 / 250) * 200 paise.Step 4: Compute (60 * 200) / 250 = 12,000 / 250.Step 5: 12,000 / 250 = 48, since 250 * 48 = 12,000.Step 6: Therefore, 200 g of potatoes cost 48 paise.

Verification / Alternative check:
The quicker approach: 200 g is 4/5 of 250 g. Hence, cost for 200 g is 4/5 of 60 paise = (4 * 60) / 5 = 240 / 5 = 48 paise. This matches the unitary method and confirms the answer.

Why Other Options Are Wrong:
54 or 56 paise suggest incorrect fraction manipulation, such as using 200 / 220 or mis-simplifying 12,000 / 250. 72 paise would be correct if 250 g cost 90 paise, not 60. 40 paise is too low and does not maintain the given rate of 60 paise per 250 g. Only 48 paise fits the direct proportionality.

Common Pitfalls:
As with similar questions, students might miscalculate the ratio between 200 g and 250 g or perform the division 12,000 / 250 incorrectly. Also, mixing paise and rupees or dropping a zero can cause errors. Carefully writing each step and checking the final magnitude (less than 60 paise for less than 250 g) helps ensure correctness.

Final Answer:
The cost of 200 grams of potatoes is 48 paise.