In a dairy farm, 20 cows eat 20 bags of husk in 20 days. In how many days one cow will eat one bag of husk? Choose the correct choice from the following
A) 1 B) 40 C) 20 D) 26 E) 30

Rationale: "explanation : one bag of husk = 20 cows per day ⇒ 20 × 1 × 20 = 1 × 20 × x for one cow = 20 days answer : c"
Answer: C