Bartering was an early way that people what?

Bartering was an early way that people trade and exchange goods. The medium of exchange are goods for goods. The one who barters needs a good from another and exchanges an unneeded good to the other who needs it as well. Now, the medium of exchange is money although bartering is still sometimes employed in terms of trade.

12 days because 1/4 is 25% of 100 if 100 is equal to 1 pound then multiply 3 by 4 which equals 12