Consumption rate of fodder per cow: In a dairy farm, 40 cows consume 40 bags of husk in 40 days at a steady rate. Based on this, in how many days will one cow consume one full bag of husk?

Introduction / Context:
This is a compound proportion problem. The total consumption is proportional to the product of the number of cows and the number of days, given a fixed per-cow-per-day rate. We convert a group consumption statement into a per-cow-per-day rate and extrapolate to a single cow with one bag.

Given Data / Assumptions:

• Cows = 40
• Bags consumed = 40
• Days = 40
• Consumption rate per cow per day is assumed constant.

Concept / Approach:
Total consumption = (rate per cow per day) * (number of cows) * (days). Solve for the rate first, then find days for 1 cow to finish 1 bag: days = 1 / (rate per cow per day).

Step-by-Step Solution:
Total cow-days = 40 * 40 = 1600 cow-daysBags per cow-day = 40 / 1600 = 1/40 bag per cow per dayDays for 1 cow to eat 1 bag = 1 / (1/40) = 40 days

Verification / Alternative check:
Check scaling: If one cow needs 40 days for one bag, then 40 cows will consume 40 bags in 40 days exactly as given. The relation is consistent.

Why Other Options Are Wrong:
15, 38, and 32 do not satisfy the implied per-cow-per-day consumption; 28 is also inconsistent with the given totals.

Common Pitfalls:
Forgetting that 40 cows * 40 days represents 1600 cow-days and not mixing up “per cow per day” with “per day” group consumption.

Final Answer:
40