Respuesta :

Answer:

10

Step-by-step explanation:

1. Create a ratio of cows to days

7:30

*NOTE: The more cows, the less time it will take

2. Multiply 7 by 3 and divide 30 by 3

You would get 21 : 10

3. You have the answer!! :D

It will 10 days for 21 cows to graze the same plot of land.

Hope this helps :)

Have a nice day!