1.  In a dairy farm, 40 cows eat 40 bags of husk in 40 days. In how many days one cow will eat one bag of husk?
A. 1
B. 1/40
C. 40
D. 80

Answer: Option C

Explanation:

Let the required number of days be x.

Less cows, More days (Indirect Proportion)

Less bags, Less days (Direct Proportion)

Cows 1 : 40 :: 40 : x
Bags 40 : 1

1 x 40 x x = 40 x 1 x 40

x = 40.