If two pounds of meat will serve 5 people, how many pounds will be needed to serve 13 people?

5.2 pounds because for 10 ppl you need 4 pounds and for 3 you need 1.2 because 5/2 equals 0.4 which you have to multiply by 3 to get the three people which gets you 1.2 so all together 1.2+4=5.2 pounds of meat.