Please help, this is geometry

Agrain trader buys the following amounts from three suppliers: 3,200 pounds, 5,100 pounds and 700 pounds. what is the total weight of his purchase?

Guests at an amusement park must be at least 54 inches tall to be able to ride the roller coaster. which graph represents the set of heights that satisfy this requirement?

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?