There are about 30 000 farms in a certain country. The average size of the farm is 1 300 sq meters. To estimate the number of square meters of farmlands in the country, you should
1. add 30 000 and 1 300
2. subtract 1 300 from 30 000
3. multiply 30 000 by 1 300
4. divide 30 000 by 1 300